Lewis Hamilton tops the timesheets on final day of Barcelona pre-season test, heading new teammate George Russell and the Red Bull pair.
The Briton posted the best time of the week in the final moments of today's session, and for a while looked set to go even quicker before opting to abort the lap.
His feat is all the more impressive when you consider that over the course of this afternoon's four hour session, which got underway in the wet as Pirelli sought to try their new wet tyres, the Briton completed 94 laps, more than any other driver.
Second quickest was teammate Russell, who, considering this afternoon was going to be used for wet-weather running, looked set to be heading into the weekend as pace-setter.
It's early days, but wrapping up the opening test with a 1-2 is a definite confidence booster from Mercedes even if Russell is playing down the team's chances.
"We're seeing some interesting things out there, that's what testing is for," said the former Williams driver, "some teams are looking pretty fast. A red team and an orange team in particular look very, very competitive.
Asked if he thought Mercedes is favourite, he was quick to respond: "Certainly not, I'm pretty sure of that. They seem to have things well under control," he added, referring to McLaren and Ferrari, "and they look very strong, low fuel and high fuel, and with tire management."
Over the course of the day, Max Verstappen and Sergio Perez added another 133 laps to the RB18's tally, while Ferrari and McLaren also continue to look good.
Indeed, while Hamilton's 94 laps were impressive, Carlos Sainz completed 92 and Daniel Ricciardo 85.
If it was looking good for Mercedes, spare a thought for Hamilton's former (favourite) teammate, Valtteri Bottas whose pre-season test has gone from bad to worse. Following the problems for teammate Guanyu Zhou this morning, Bottas only managed ten laps this afternoon.
Indeed a number of teams had issues, with Alpine, Haas and Aston Martin all bringing their tests to an early end and Yuki Tsunoda not getting in any running following Pierre Gasly's crash this morning.
Alpine called it a day before lunch, the French team citing a hydraulics issue. This afternoon, Aston Martin and Haas both followed suit and called it quits.
"The team has determined that it was an oil leak that caused Vettel to stop on track shortly before lunch," said Aston Martin. "The oil leak caused a small fire but with the car now back in the garage, we are investigating where the issue came from."
"Whilst we'd hoped that the car would be able to return this afternoon, the repair work is going to take several more hours," said Haas, "so unfortunately we will not be back on track today."
While full wets were the order of the day after lunch, the army of water tankers having done their work, the track soon dried sufficiently to allow the switch to Inters.
Though the sun appeared to have gone on holiday, drivers were subsequently able to switch to slicks and with ninety minutes still remaining the times were tumbling.
The teams now head back to their various bases where they will analyse the data acquired over the last three days in preparation for the Bahrain test and the season-opening Grand Prix that follows days later.
For all the fuss about Alfa Romeo's camouflage livery they might as well have run the C42 in its 2022 glory, such was the amount of time the car spent in its garage.
Sadly, like Alfa Romeo, Haas is another team that appears to have its work cut out in the days (and possibly months) ahead. Like Alpha Tauri, where Tsunoda never got to run this afternoon, the American team's issues meant that Mick Schumacher was unable to participate.
In just under two weeks the final - indeed, according to F1, only pre-season test gets underway, and as the action switches to Bahrain things are likely to hot up in every sense.
Other than expecting to see the cars looing slightly different to what we have witnessed this week it is going to be interesting to see how they have dealt with the porpoising issue, unless they don't expect to see anything remotely fishy in the desert.
At Mercedes, Russell was out first, covering valuable miles and experimenting with the car set-up to further the team's understanding of the bouncing issue being experienced with this new generation of car.
The circuit was wetted at lunchtime via tanker, offering Lewis the chance to run the Intermediate tyre before moving to a dry set-up to perform a tyre sweep from the C3 to C5 compounds. Hamilton would go on to complete 94 laps, banking solid learning to build on in the official pre-season test in Bahrain in two weeks' time.
"It's been an interesting few days," said the seven-time champion, "it's not been the easiest or smoothest running - we have some obstacles to overcome. We'd always want more laps but I'm happy with today's running, I got almost 100 laps in today which for half a day's running, isn't too bad. The car is a lot different to drive than in previous years, as are the tyres, but we're working our way through our programme.
"The whole team have done an amazing job this week," he continued, "the men and women back at the factory have worked so hard, we've got a lot of data to go through from these three days and we'll just put one foot in front of the other and put in the work. It was good to get a feel for the different tyre compounds but you never know where you are compared to the other teams on the first days of running."
"The three days in Barcelona have been incredibly intriguing," added Russell. "I don't think the lap times are very representative at all, we were top of the timesheets today on the C5 compound which is incredibly strong around Barcelona, but I wouldn't read much into it.
"The Ferrari and McLaren look strong and I think we've got lots of improvements to make, we're not fully happy with the balance of the car and the other limitations we have currently. But it is only testing, we're here to learn and we have made some important experiments this week and have a good idea of the direction we need to go in."
"We're pleased with how the week has gone," said Andrew Shovlin, "we planned a very busy programme for the three days and we managed to get through the high priority items, making good progress with the car and power unit. It has taken a huge effort from the team in Brackley and Brixworth to bring the W13 to the track so it's very satisfying for everyone to see it cover 1800km without significant issues, and to show good promise from a pace point of view. We've learnt a huge amount over the last few days and still have a lot of data to go through ahead of Bahrain. The rate of progression is going to be very high for all teams and whilst we look to be in a good place here, we need to be mindful that our competitors may have a lot of performance to come between now and the first race.
"We'll be working with the drivers on the simulator over the next few days; we've still got work to do tuning the balance both for single lap and long run. Bahrain is a very different circuit to a cold Barcelona but hopefully we can make good progress in those areas and build on what has been a promising start to our winter testing programme."
Red Bull finished a productive week, with Max Verstappen running during the morning session and Checo Perez taking over the wheel for the afternoon.
The world champion completed 59 laps in the RB18 before Perez clocked up 74 in some wet weather conditions at a cloudy Circuit de Barcelona Catalunya.
"Everything worked well in the running we got and the car felt good," said Verstappen, "but our morning was somewhat interrupted by a number of red flags across the session so we couldn't complete all of our planned programme. We just continued from what I did on day one and I think that was the most important objective for Barcelona.
"What is positive is that the car is running smoothly," he added, "I don't pay attention to the lap times just yet, I will look into that when we get into Q3 in Bahrain. I just focus on doing a lot of laps and nailing down every single aspect of the car. I have really enjoyed driving the RB18 this week, it has a nice stable balance and I think it looks cool as well so it's good to jump into. I think following does seem a little easier in these cars, of course we won't know if there is any real change until race one when everyone is on the same tyres and fuel, but my initial thoughts are that I do think it's a step forward."
"I think we have a good baseline and good potential," added Perez. "It is obviously early days, but I am really hopeful we will make some good steps before Bahrain and keep progressing with all the information we are going to gather from Barcelona. It is important to keep learning from my driving and the way I am adapting to the car and my team and then what the best way will be to maximise that. I think this season the challenge will be about maximising the whole weekend under the new regulations."
"We had a good day today," said Head of Race Engineering, Guillaume Rocquelin, "the drivers were happy and we started to put in some decent lap times. To sum up the week I would say it has been a very promising few days with this new car and the most pleasing thing for me is that we have got a solid platform and direction to build from. We will consolidate some things that we have learnt here before Bahrain, but it is more considerate than a big step."
"It was a shame not to complete any laps this afternoon," admitted Lance Stroll, "but it has been great to be back behind the wheel of a Formula One car. We have already learned a lot about the AMR22, which is important because the cars are so different this year. It is a whole new philosophy to understand so we are working through how these cars like to be set up and driven. We are on a big learning curve now, like all the teams, and the goal is to continue to make progress in Bahrain in the next test, and we will still be doing so in the early races too."
Check out our Friday gallery from Barcelona, here.