Though not nearly as radical as anticipated, the upgrade package on the RB18 sees Sergio Perez top the timesheets on the final morning of Bahrain test.

While not exactly a damp squib, when the shutters were removed and the RB18 finally appeared there was nothing like the reaction witnessed on Thursday when Mercedes revealed those sidepods.

True, the revised sidepods on the RB18 appear sculpted but not nearly as radical as the Mercedes. The angle of the sidepods appears to have changed, and the cooling inlets moved, while the floor features some additional curves.

However, first timed lap out of the box and the Mexican went quickest, crossing the line at 34.733, 0.132s quicker than the previous best posted by Pierre Gasly.

As the TV cameras cut to the Red Bull garage, Helmut Marko was smiling.

Having gone quickest once everyone else had gone home yesterday, this morning 'Sneaky Pete' Magnussen was at it again, as Haas had an hour of running before its rivals. Later today, when the session finishes at 19:00 (local time), teammate Mick Schumacher will get two hours of additional track time.

Unfortunately, despite the additional time allotted to the American outfit, a water pressure leak and then a fuel system issue restricted Magnussen to just 38 laps, the fewest of the ten drivers on duty.

There was some good news for McLaren as the updated parts, including new brake ducts, had arrived overnight, thereby, hopefully allowing Lando Norris to complete some longer runs.

The initial running was all about data acquisition and therefore aero rakes were much in evidence, however, as the rakes were dumped and the times decreased Sainz and Gasly dominated the top of the timesheets.

As Zhou went quickest, work continued on Hamilton's Mercedes as the Briton continues to struggle with the car's handling.

With his teammate sidelined by COVID, it fell to Norris to test two different floors on the McLaren as the Woking outfit seeks to overcome its cooling issues.

Both the Alpine and the Red Bull were visibly porpoising this morning, on-board footage from the French car revealing just how much of a pounding Fernando Alonso was taking.

Just over an hour before the end of the session, we were treated to what is hopefully the shape of things to come, as Hamilton and Gasly put the new regulations to the test.

As the pair battled, at one stage, as they passed Perez, they were three abreast. The 'skirmish' lasted for a few laps, with Hamilton, who was on a race sim, eventually pulling away, but for those few brief laps it was clear that cars can follow more closely this year, the pair passing one another over and over again.

As Hamilton continued on his race sim, Christian Horner, of whom we have heard worryingly little in recent months, opined that it is still impossible to call the pecking order, the Briton surprised at the lack of long runs, indeed race sims, over the course of the test.

As was the case yesterday, the session concluded with a red flag for system checking purposes. The order subsequently went out that there would be a standing start.

Only four drivers bothered to turn out, Gasly, Perez, Stroll and Zhou, and though the first 'start' had to be aborted, the second attempt saw the Frenchman lead the way into the first corner.

Just 619 laps this morning with Gasly completing the most (91), ahead of Zhou (82) and Hamilton (78), while Magnussen completed the least (38).

The top three, Perez, Zhou and Gasly set their times on the C4, while fourth-placed Sainz was on the softer C5. Norris, who completed just 39 laps, was the quickest C3 runner, finishing the morning sixth overall.

This afternoon, as we anticipate conditions to next weekend’s race, we can expect lap times to lower, while there is also talk of further upgrades to the RB18 as world champion Max Verstappen takes over.

Check out our Saturday gallery from Bahrain, here.