Ferrari's Sebastian Vettel was quickest in final Formula 1 practice for the Austrian Grand Prix, with rain mid-session preventing the leading teams from completing qualifying simulations.
The four-time world champion clocked a 1m09.994 on the soft compound tyres, 0.017s quicker than Mercedes' Lewis Hamilton with Kimi Raikkonen third in the other Ferrari.
With rain a distinct possibility for qualifying, several drivers went out on the full wet tyre when rain hit halfway through the session - although Hamilton was the only one of the frontrunners not to do so.
A number were caught out by the slippery conditions, with Vettel running off track at Turn 2 before recovering while Toro Rosso's Carlos Sainz spun down at Turn 6.
Hamilton and Mercedes team-mate Nico Rosberg traded times at the top of the timesheets in the early part of the session before Vettel usurped them both.
Hamilton was on course to reclaim top spot, having clocked the fastest first and second sectors, but he ran wide after getting out of shape in the final corner.
Drivers were told rain was expected at the midpoint of the one-hour session, with Force India's Sergio Perez - who had a puncture that Pirelli said was rim-related early on - reacting immediately.
The Mexican clocked the fourth fastest time on super-softs, but before Mercedes and Ferrari could get out on track on the softer tyre, McLaren's Fernando Alonso brought out the red flag when he stopped on the pit straight.
As the marshals cleared Alonso's car, which is heavily upgraded this weekend but will incur a penalty of at least 20 places due to engine component changes, rain began to fall.
Both Mercedes and Ferrari queued up at the end of the pitlane on the super-soft tyres, but by the time they headed out, the rain had intensified.
Rosberg and Raikkonen skated off track but kept their respective cars out of the barriers before retreating back to the pits.
Rosberg ended up fifth fastest, three tenths slower than team-mate Hamilton, ahead of the Williams' of Felipe Massa and Valtteri Bottas.
Toro Rosso's Max Verstappen was eighth with Lotus drivers Pastor Maldonado and Romain Grosjean completing the top 10.
Force India's Nico Hulkenberg - who said on Friday that it took him some time to get used to driving the car following his victory at Le Mans, was 11th with Sauber's Marcus Ericsson's 12th.
Sainz was 13th, and was told by his engineer that he was the fastest car on the wet tyre in the closing stages, ahead of Red Bull's Daniil Kvyat and Alonso.
Daniel Ricciardo had a quiet session in the other Red Bull, managing just 10 laps for 16th, but that was two more than Sauber's Felipe Nasr completed in 17th.
McLaren's Jenson Button was 18th, with the Manor-run Marussias of Will Stevens and Roberto Merhi bringing up the rear.
FREE PRACTICE 3 TIMES
|4||Sergio Perez||Force India/Mercedes||0.227s||14|
|8||Max Verstappen||Toro Rosso/Renault||0.442s||23|
|11||Nico Hulkenberg||Force India/Mercedes||1.015s||14|
|13||Carlos Sainz Jr.||Toro Rosso/Renault||1.145s||18|
|14||Daniil Kvyat||Red Bull/Renault||1.145s||14|
|16||Daniel Ricciardo||Red Bull/Renault||1.825s||10|