MANAMA (Reuters) - Williams driver George Russell swapped the slowest car in Formula One for the championship-leading Mercedes on Wednesday and enjoyed a day back on top of the timesheets in Bahrain testing.
The 21-year-old Mercedes-backed Briton, last year's Formula Two title winner, has languished at the rear of the field since he made his F1 debut with struggling former champions Williams in Australia last month.
Russell tested with champions Mercedes last year, setting a track record in Hungary in August, and enjoyed being back up to speed with a best lap of one minute 29.029 seconds at the Sakhir circuit.
His time, in warm and dry conditions after Tuesday's rain, was the fastest over the two days of testing in Bahrain following Sunday's grand prix won by Mercedes' five times champion Lewis Hamilton.
Mexican Sergio Perez was second fastest for Racing Point, also on the softest C5 compound, with Ferrari's Sebastian Vettel third on the harder C3.
Mick Schumacher, the 20-year-old son of seven times world champion Michael, drove for Alfa Romeo after making his Formula One test debut in the Ferrari on Tuesday and ended the day sixth fastest with 70 laps.
Thai driver Alexander Albon completed the most laps, a whopping 143 for Toro Rosso, while British 19-year-old Dan Ticktum did 135 on his test debut for Red Bull.
Canadian Nicholas Latifi, the reserve driver testing the Williams, was slowest in 1:32.198.
(Writing by Alan Baldwin in London, editing by Toby Davis)