Ferrari turned the tables on Mercedes in the final practice session for the Spanish Grand Prix after Kimi Raikkonen set the fastest time of the weekend on Saturday morning.
After Mercedes held the upper hand throughout Friday practice, Ferrari upped its game in FP3 as Raikkonen found a full second in performance on his FP2 run. Raikkonen, who appears to be experiencing a return to form this weekend in Spain, was 0.242s clear of Ferrari teammate Sebastian Vettel at the top of the timsheets and 0.381s clear of Lewis Hamilton in the fastest Mercedes.
After problems on Friday afternoon, Ferrari has yet to rid Vettel's car of all its gremlins and he completed just seven laps in FP3. One of those laps was a qualifying simulation, but when he attempted to return to the track for a final run his car stopped midway down the pit lane and had to be wheeled back to the garage.
Mercedes also had problems, with Valtteri Bottas stuck in the garage for 50 minutes as the team changed his power unit. The mechanics stayed late on Friday night to fix an electrical issue, but as the team was rebuilding car No.77 on Saturday morning they found a water leak that required a full power unit change. The switch saw Bottas' car revert to the engine used at the opening four rounds of the season and he will stick with that power unit for the rest of the weekend.
Red Bull finished the session fifth and sixth, with Max Verstappen 0.811s off Raikkonen and Ricciardo a further 0.2s adrift. Both cars lost nearly 0.5s in the middle sector of the lap, which is mainly made up of high- and medium-speed sweeping corners.
Nico Hulkenberg continued to impress in the Renault with the seventh fastest time ahead of Felipe Massa in the Williams and Carlos Sainz in the Toro Rosso. Fernando Alonso snuck into the top ten after 16 laps in the McLaren-Honda without any major issues. He was 1.8s off Raikkonen's pace but looks to be in a genuine battle with the Haas and Force India drivers occupying the four places behind him and all within 0.21s of the McLaren's fastest lap.
Daniil Kvyat continued to lap off the pace of teammate Sainz down in 15th ahead of a good lap from Marcus Ericsson in the Sauber. Lance Stroll was 0.8s off Williams teammate Massa but ahead of Jolyon Palmer, Stoffel Vandoorne and Pascal Wehrlein.