What happened: Kimi Antonelli put Mercedes on top of final practice at Sepang after the team opened the Bahrain Grand Prix weekend in Malaysia off its usual pace. Mercedes had managed only second and fifth in FP1, then seventh and eighth in FP2, despite bringing a heavily upgraded W17 to the circuit.
Why it matters: The rebound matters because Antonelli arrives as the championship leader and Mercedes is trying to turn its Sepang upgrade package into another clean weekend. It also gives an early lift to the new floor and sidepods Mercedes brought to Malaysia before qualifying sets the grid for round 16.
By the numbers: Mercedes' Friday session placements were 2nd and 5th in FP1, then 7th and 8th in FP2, before Antonelli moved the upgraded car to the top in FP3.
What to watch: Qualifying is next at Sepang, where Mercedes will find out whether the Saturday rebound holds over a full push lap. Sunday will show whether the upgrades also restore the car's longer-run edge.