Sebastian Vettel led the way in Saturday's rain-hit practice session for the Chinese Grand Prix.
The Ferrari driver posted a best lap of one minute and 57.351 seconds at the Shanghai International Circuit to finish ahead of the Williams of Valtteri Bottas and Force India's Sergio Perez.
Both world champion Lewis Hamilton and his Mercedes team-mate Nico Rosberg, winner of the opening two races, did not bother to post a competitive lap in the tricky conditions.
The Mercedes duo were among eight drivers who opted against setting a time to avoid the risk of sustaining any damage ahead of qualifying later on Saturday.
Bottas was the first driver to brave the wet track with 15 minutes of the one-hour session gone. The Williams driver tippy-toed his way around the damp circuit, but as the rain, which is also forecast for qualifying, started to ease off, he was joined by a number of other drivers.
Renault's Kevin Magnussen was on track, too, having missed the entirety of Friday's second practice session after a car failure which led to a left-rear tyre blow-out.
The Dane encountered no further problems, but team-mate Jolyon Palmer limped back to the pits with a puncture, this time on the right-rear of his Renault, which is likely to cause some concern to the French manufacturer. The Briton returned to the track to post the sixth best time of the morning.
Qualifying, which is due to start at 3pm local time, will see the sport revert to last year's format after the unpopular elimination-style system was dropped following just two outings.