It was a stunning comeback from the Spaniard, who had lost track time on Thursday, and spent this morning's free practice session working hard to dial in the set-up to his liking. Even during Q2, he declared himself unhappy with the balance, but pulled everything out of the car on his final lap in Q3.
After showing well all weekend, Stoffel's car developed a minor problem just ahead of qualifying. With the clock ticking, his crew were unable to resolve the issue, which meant Stoff went into this afternoon's session with a slight performance drop-off. Despite the issue, he qualified 12th and will be able to run without problems tomorrow.
Fernando Alonso: "We were a little bit worried after finishing FP3 in 15th position - we lacked some pace and the balance was not ideal. But the team did a great job ahead of qualifying: we changed the car completely, a bit like throwing a coin in the air and having everything work out fine.
"This afternoon's session was a little bit stressful - there was a lot of traffic, and you really needed to deliver a lap when your tyres are at their newest, and then wait and see if your time is good enough. That's quite tense, but at the same time it's very challenging.
"Tomorrow is going to be a long race. We just need to stay away from the walls and bring the car home with the best possible result. That's going to mean securing your starting position on the first lap and then playing with the strategy.
"Key to this race will be the tyres - the Hypersoft has very high degradation, so we'll need to manage that."
Stoffel Vandoorne: "We had a competitive car in FP3, but then discovered a small problem before qualifying. There was no time to fix it, so we had to go into this afternoon's session without the right settings. Immediately, it felt a bit different; not as good as FP3, and a little bit unbalanced.
"That wasn't ideal for qualifying, but won't be a worry for tomorrow as it can be fixed.
"We were still very competitive considering what happened; we had good pace in Q1 and Q2, and were a bit closer up the field. A bit of traffic on my out-laps and not-the-most perfect lap meant I finished 12th. We were two tenths up on the delta, so I think it would've been easy to get into Q3.
"I'm obviously disappointed, but there's definitely the potential for points tomorrow. We can decide on our starting tyre: the Hypersoft doesn't look to be the best race tyre, so starting on a different compound could hopefully open some doors for us. We'll just need a bit of luck on our side tomorrow."
Eric Boullier: "Starting the Monaco Grand Prix from seventh and 12th positions gives us a extremely good opportunity to score points tomorrow.
"This is our best collective qualifying performance of the season so far, and is a real testament to the effort of the whole team, who have worked incredibly hard to bring new components to the track, evaluate them and ensure they perform smoothly. Coupled to that, both Fernando and Stoffel have driven with commitment and precision all weekend - and, but for a small problem with Stoffel's car, I think we could have started both drivers inside the top 10.
"Seeing this sort of validation is hugely encouraging for the whole team. Let's hope we can bring the weekend to a conclusion with a strong performance in the race - I strongly believe we can."
Check out our Saturday gallery from Monaco, here.