Nico Rosberg set the quickest time during second practice for the Austrian Grand Prix as brief dry spells sandwiched a period of heavy rain.
Rosberg, who topped the opening session, clocked a time of 1:07.967 as the field posted only a handful of laps before a downpour affected the region.
Drivers tiptoed their way back to the pit lane when conditions rapidly worsened within the first 10 minutes, as Sergio Pérez spun at slow speed.
Daniel Ricciardo broke the silence after half an hour of no action to lead the drivers onto the circuit, with all plumping for the Intermediate compound.
Several corners of the circuit were dry, but the final couple of corners necessitated prolonged use of the wet tyres.
Ferrari was the first to switch to slicks with 20 minutes remaining as Sebastian Vettel headed out on the Ultra Soft tyres, followed by several rivals.
After an initial period of tardy lap times, an array of drivers found improvements, with Lewis Hamilton clocking a time just 0.019s down on Rosberg’s initial benchmark.
Rosberg improved to the tune of six tenths across the first two sectors of the lap but elected to pit, just before Vettel went off at high speed on the approach to Turn 2.
Vettel’s Ferrari veered out of control when his rears locked when he braked for the uphill Turn 2 and the German driver spun through the gravel, but fortunately stopped short of the barriers.
The Virtual Safety Car was deployed, denying rivals the opportunity to improve their lap times.
Rosberg thus finished 0.019s clear of Hamilton, with Force India’s Nico Hülkenberg in third place.
Vettel was fourth despite his off, ahead of Ricciardo, Carlos Sainz Jr., Max Verstappen and Kimi Räikkönen, who took a trip through the Turn 5 gravel trap during the first dry spell.
Valtteri Bottas placed ninth for Williams, in front of McLaren pair Jenson Button and Fernando Alonso.
Feliple Massa was 12th, ahead of Daniil Kvyat, Pérez and Renault duo Kevin Magnussen and Jolyon Palmer.
Pascal Wehrlein was an encouraging 17th for Manor, building on his form from the morning session, with Esteban Gutiérrez the lead Haas driver in a low-key 18th.
Marcus Ericsson and Felipe Nasr sandwiched Romain Grosjean, with Rio Haryanto completing the runners.