ABU DHABI - George Russell, the only Formula One driver without a point this year, swapped his tail-end Williams for a title-winning Mercedes on Wednesday and ended up fastest on the final day of post-season testing in Abu Dhabi.
The Mercedes-backed rookie did 145 laps of the Yas Marina circuit, the second most of the day, with a fastest lap of one minute 37.204 seconds - more than three seconds quicker than his time for Williams on Tuesday.
Ferrari's Charles Leclerc crashed, bringing out red flags, but was still second fastest.
Russell's time for the champions compared to Tuesday's best, set by regular Mercedes race driver Valtteri Bottas, of 1:37.124.
Russell outqualified departing team mate Robert Kubica 21-0 this season but finished last overall after the Pole managed to score a point in Germany - the former champions' only top-10 finish of the campaign.