Lewis Hamilton landed the first blow leading the opening practice session for this weekend's United States Grand Prix.
After a slightly damp start, a typically dusty track remained meaning grip levels were very low for the drivers as the hard work of setting up their cars and testing new parts began at the Circuit of the Americas.
Mercedes straight to the top
As we have become accustom to in 2014, Mercedes were quick to seize the initiative moving to the top with around half an hour to go in the 90-minute session. Hamilton went quickest and then proceeded to knock a few hundredths off his best time every lap in a short stint culminating in being the only man to break the 100-second barrier with a 1:39.941.
As for Rosberg a few mistakes on his quicker laps meant he wasn't quite able to match his team-mate but his best time by session's end was with within three tenths of Hamilton and good enough for second.
McLaren renaissance continues
After their best race of the year in Sochi three weeks ago, McLaren continued their return to form in first practice in Austin.
Jenson Button and Kevin Magnussen led much of the early running in a rare one-two but even after Mercedes had begun to flex their muscles still had both cars in the top five as Button claimed third with Magnussen fifth.
While the Circuit of the Americas doesn't suit the strengths of the MP4-29 quite as well as the streets of the Olympic Park it seems the push for upgrades until the end of the season is helping them in their final races with Mercedes power.
Mixed fortunes at Red Bull & Ferrari
After the straights in Sochi benefited the Mercedes-powered cars it was thought that the more aero-dependent layout at COTA would bring Ferrari and Red Bull back into play.
However, quite where the two teams will feature this weekend appears uncertain. Fernando Alonso and Sebastian Vettel were where most thought with the Spaniard sixth and the German seventh but their team-mates struggled as Kimi Raikkonen was 12th with Daniel Ricciardo 17th.
For the Australian his session was brought to an early end as an ERS issue kept him confined to the garage as the circuit continued to improve while the Finn's struggles to find a good balance continued in his Ferrari.
Kvyat stars as Verstappen returns
After the hopes of a nation were dashed by a poor home race in Russia three weeks ago, Daniil Kvyat looks back on the pace again in Texas. The Russian was fourth quickest in the Toro Rosso and the last man within a second of the leading Mercedes.
In Sochi it was the higher-than-expected fuel consumption that hit the 20-year-old's race, however, with no such problems this weekend, if he can continue his strong start could be a contender for fastest Red Bull-backed driver.
After sitting out in Sochi, Toro Rosso's 2015 driver Max Verstappen returned to the cockpit in Austin. The 17-year-old impressed on debut in Suzuka a month ago and was within the top 10 again in first practice albeit nearly a second slower than the man he'll replace at the Italian team.
Nasr impresses at Williams
The other young driver participating in the first practice session was Williams' reserve Felipe Nasr, in place of Valtteri Bottas.
While the team, that most expect to be 'best of the rest' behind Mercedes this weekend, had their usual quiet start the Brazilian GP2 star impressed beating his compatriot Felipe Massa by three tenths of a second. Nasr ended the session eighth with a 1:41.546 as Massa was eleventh.
Grosjean brings up depleted grid
The big story heading into the weekend was the loss of Caterham and Marussia from the grid leaving just 18 cars to race in Austin.
While their absence was noticeable by the small timing tower that accompanies the F1 coverage the real impact was minimal in terms of action. What it did mean, however, was that Romain Grosjean, a man who finished on the podium here last year, was last in the Lotus.
The Frenchman was testing a new 2015-spec front wing on the E22 and was six tenths slower than the next placed car of Ricciardo.
Look ahead to FP2
Heading into the afternoon, or evening session if you are in Europe, session there will be several areas to watch out for. The drivers will use the Pirelli soft tyres for the first time ever at COTA and despite quite cool temperatures in the morning, seeing how durable they will be in the race simulation this afternoon will be key to how many stops to expect during the race.
Also the relative pace of Red Bull and Ferrari compared to the Williams and Mercedes during the long run will be a key area of note. If the soft tyres do wear then that could be to the advantage of the non-Mercedes powered teams who are traditionally closer in the race trim than over a single lap.
But most important will be the battle between Hamilton and Rosberg out front, can te championship leader continue his momentum from the morning or will Rosberg strike back in the afternoon? We'll have to wait and see.
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