SPIELBERG, Austria -- Sebastian Vettel set the fastest time in final practice for the Austrian Grand Prix as title rival Lewis Hamilton encountered more problems with his Mercedes.
Vettel set the fastest times in all three sectors of the lap as he went on the attack with ten minutes of the session remaining with a series of quick laps on the ultra-soft compound tyres. On his fastest lap he came across Hamilton in the final sector, but managed to negotiate his way past the Mercedes to light up the timing screens and set the fastest lap, 0.269s quicker than his title rival.
Valtteri Bottas was third fastest for Mercedes, 0.423s off Vettel, while Kimi Raikkonen was 0.519s off his teammate in the second Ferrari.
Hamilton was on a quick lap when he suffered a right front brake issue and continued straight at Turn 3 and into the run off. A puff of black smoke came from the front right wheel and the team later confirmed that an issue on the "team's side" -- not from the brake supplier -- had caused the problem. Mercedes will be able to fix the issue in the break before qualifying.
The issue is just another stumbling block in an already difficult weekend for Hamilton, who is facing a five-place grid penalty after Mercedes detected a problem with his race gearbox following the Azerbaijan Grand Prix and was forced to replace it this weekend. The change broke the six race cycle a gearbox must last, meaning the highest he can hope to qualify on Sunday's grid is sixth (assuming other cars in the top five don't also receive a penalty).
Max Verstappen set the fifth fastest time with a lap 0.692s off Vettel and 0.112s quicker than Red Bull teammate Daniel Ricciardo. Both Red Bull drivers made up for lost time on Friday afternoon by completing a heavy-fuel run on the ultra-soft tyres on Saturday morning, but their times were roughly 0.5s per lap slower than the pace Hamilton had shown in FP2.
Haas finished the session seventh and eighth, with Kevin Magnussen beating teammate Romain Grosjean by 0.079s. The two Toro Rossos of Daniil Kvyat and Carlos Sainz were ninth and tenth as once again Mercedes' customer teams failed to feature in the top ten at what is considered to be a power circuit. Sainz's car came to a halt exiting Turn 1 early in the session, but the Toro Rosso was recovered to the pits and sent back out later in the session.
Esteban Ocon was 11th in the Force India ahead of Nico Hulkenberg in the Renault and Stoffel Vandoorne in the McLaren. Jolyon Palmer's Renault was 14th ahead of Fernando Alonso's McLaren, which developed an MGU-H problem on Friday forcing the team to remove the new 'spec three' Honda power unit from his car overnight and replace it with a less powerful 'spec two' unit.
Williams drivers Lance Stroll and Felipe Massa were 16th and 17th ahead of Sergio Perez who continued to struggle in the Force India down in 18th. Marcus Ericsson beat Pascal Wehrlein by 0.090s in the battle of the Saubers, which is likely to make up the back row of the grid.