Valtteri Bottas brought Mercedes' run of P1s to an end in final practice in Austria as the Williams driver beat Lewis Hamilton by 0.05s.
Although Kevin Magnussen set the first time of the session, a 1:16.6, he soon found himself in second place and by some margin as Nico Rosberg crossed the line with a 1:12.9.
Magnussen, though, came back with a 1:11.4 while Rosberg improved to stay second. Lewis Hamilton put his W05 up into third place.
As the trio continued lapping, Magnussen lowered the benchmark to a 1:10.998 but that was soon bettered by both Williams drivers, Felipe Massa going quickest ahead of Bottas.
The Williams duo swapped positions with Bottas edging ahead by 0.036s while Fernando Alonso climbed to third place, 0.135s down.
It was, however, all change again when the Mercedes drivers returned to the action for their second stint of the morning. Rosberg hit the front with a 1:10.058 while Hamilton, despite a few good sectors on different laps, only moved up to fifth.
With 15 minutes remaining in the session, the drivers began to swap to the supersoft tyres. But with the track temperature dropping by a few degrees, getting heat into the rubber proved a problem for some.
Fernando Alonso went quickest on his second supersoft lap only to be pipped by Bottas who in turn lost out to Massa. The Brazilian also needed a second flying lap to clock his 1:09.901.
The session appeared as if it would end with another Mercedes P1 as Hamilton crossed the line with a 1:09.898 only for the Brit's time to be beaten by Bottas by 0.050s. Massa was third, a further 0.003s down.
Meanwhile, there were problems for Jenson Button who reported that he had "no engine braking at all." Pulling into the pits, McLaren had to deal with a "small brake fire" before putting his MP4-29 up on a jacks where it remained for the rest of final practice.
01 Valtteri Bottas Williams 1:09.848 22 laps
02 Lewis Hamilton Mercedes 1:09.898 +0.050 25 laps
03 Felipe Massa Williams 1:09.901 +0.053 21 laps
04 Daniil Kvyat Toro Rosso 1:09.927 +0.079 25 laps
05 Nico Rosberg Mercedes 1:09.999 +0.151 31 laps
06 Fernando Alonso Ferrari 1:10.054 +0.206 17 laps
07 Daniel Ricciardo Red Bull 1:10.392 +0.544 19 laps
08 Kevin Magnussen McLaren 1:10.449 +0.601 23 laps
09 Kimi Raikkonen Ferrari 1:10.488 +0.640 22 laps
10 Sebastian Vettel Red Bull 1:10.562 +0.714 21 laps
11 Nico Hulkenberg Force India 1:10.683 +0.835 22 laps
12 Pastor Maldonado Lotus 1:10.776 +0.928 26 laps
13 Jean-Eric Vergne Toro Rosso 1:11.043 +.195 22 laps
14 Romain Grosjean Lotus 1:11.103 +1.255 22 laps
15 Sergio Perez Force India 1:11.235 +1.387 18 laps
16 Adrian Sutil Sauber 1:11.294 +1.446 24 laps
17 Esteban Gutierrez Sauber 1:11.558 +1.710 23 laps
18 Jules Bianchi Marussia 1:11.848 +2.000 21 laps
19 Kamui Kobayashi Caterham 1:12.320 +2.472 23 laps
20 Marcus Ericsson Caterham 1:12.892 +3.044 27 laps
21 Max Chilton Marussia 1:12.915 +3.067 14 laps
22 Jenson Button McLaren 1:14.237 +4.389 4 laps