Hamilton and Rosberg yet again set the practice pace
Predictably, Mercedes pair are fastest in first sessions for Austrian Grand Prix as defending F1 champion Sebastian Vettel spins twice
Agencies in Spielberg, Austria
Formula One leaders Mercedes showed they were undaunted by a new track to dominate the first practice sessions ahead of Sunday's returning Austrian Grand Prix.
Lewis Hamilton set the fastest lap of the day at one minute and 9.542 seconds, finishing 0.377 seconds ahead of teammate and current championship leader Nico Rosberg in the second practice session.
In the morning, it was Rosberg who had led the field ahead of Hamilton around the 4.3-kilometre Red Bull Ring track.
The two Mercedes drivers were the only ones to dip below the 1min 10sec mark, showing they were at ease on the historic Spielberg track, despite this being their first F1 outing on it.
The last time Spielberg hosted a Formula One event was in 2003.
Prior experience indeed seemed to play a major role with Fernando Alonso, Felipe Massa and Jenson Button - all of whom raced there a decade ago - clocking some of the fastest times behind Mercedes.
But drivers have insisted their initial lack of knowledge will hardly matter once the first practice sessions are done and dusted.
Red Bull struggled despite racing at home, with four-time champion Sebastian Vettel and Canadian Grand Prix winner Daniel Ricciardo setting just the sixth and eighth fastest times, over 1.2 seconds behind pace-setter Hamilton.
One of the most dramatic scenes on Friday saw Vettel go into a spin after going wide in the last turn leading into the final straight.
He was not the only one to get caught on that tricky corner, as Ricciardo and Lotus driver Romain Grosjean also bit into the side of the track.
"They were just warming up the crowd," Red Bull team boss Christian Horner joked.
"We are trying to find out the limit, and both [Vettel and Ricciardo] just came on the grass. There was also a little bit of rain in the air. Thankfully everything is fine."
Despite the spin-offs, Ricciardo reckons his Canadian Grand Prix victory will give Red Bull an extra lift for their home race in Austria, even if Mercedes remain some way ahead.
"Definitely the win gave us more motivation, not that we didn't have it but it's given us that extra little bit," he said
"It's encouraged everyone to want more of it," added the Australian of his first grand prix success the weekend before last.
"I saw the team on the pit wall when I crossed the line and it was as if it was their first win again in Formula One. It was refreshing, so the motivation is there.
"I think it's still going to take a bit of time, it's not going to happen overnight, the gap is big as we all know, but hopefully we can stand on the top step again this year and try to close them down. We're chipping away at it."
Until Montreal, the title-chasing Mercedes duo of Hamilton and Rosberg had won every race this season.
They have still started all of them on pole position and will again be favourites in Austria, home of the team's non-executive chairman and retired triple champion Niki Lauda.
But Ricciardo showed in Canada that Red Bull, winners of four titles in a row but who struggled with their new Renault V6 turbo hybrid power unit in the opening races, are increasingly a force to reckon with again.
Ricciardo is 19 points ahead of quadruple world champion Vettel in the standings after seven races but he was sure the German was chafing at the situation and could be expected to fight back.
"He showed a lot of respect and good sportsmanship after the race," said Ricciardo.
"I think it's just going to make him more motivated so I obviously can't rest now, I can't get too complacent, got to keep pushing and hopefully it works well for both of us."
Ricciardo said he had done simulator work to learn the unfamiliar layout last week and had driven it last year on a filming day with Toro Rosso.
"I've been around the track but just a few times. It's a short lap and we won't take too long to adapt and get used to it," the Australian said.
Agence France Presse, Associated Press, Reuters