Mark Webber had the measure over his rivals in Friday's opening practice in Spain, finishing ahead of his team-mate Sebastian Vettel.
Many arrived at the Circuit de Catalunya for this weekend's grand prix, predicting that the Red Bulls would hold the advantage. And that's exactly what they did in Practice One.
2010 Spanish GP victor Webber posted a 1:25.142 to finish 1.007s ahead of Vettel, who was not able to use his KERS during the 90-minute long session.
Nico Rosberg came home in third place with Spain's Fernando Alonso, who on Thursday announced he would remain with Ferrari until the end of 2016, posting the fourth best time.
It was a solid start to the weekend for Sergio Perez, who finished in fifth place, ahead of Lewis Hamilton, Michael Schumacher and Nick Heidfeld.
Report: With the early morning sun beating down on the Circuit de Catalunya, Heikki Kovalainen was the first to venture out for his installation lap, leading out a train of cars including the flow-painted Williams of Rubens Barrichello. Felipe Massa was quick to set the first time of the day, a 1:47.387 for the Ferrari driver, quite a way off the 1:21.268 set by Michael Schumacher as the fastest pre-season time at the Spanish track.
Kamui Kobayashi easily topped Massa's time before losing out to his Sauber team-mate Sergio Perez with Lewis Hamilton slotting into second place. Jenson Button took second off his team-mate.
Mark Webber was the next to lead the way with a 1:25.142, a massive 1.458s up on second placed Sebastian Vettel, in what proved to be a rather uneventful first half of practice. Drivers put in the laps and aside from Virgin having a hot blown diffuser, there were no incidents.
Halfway: Webber, Vettel, Button, Perez, Michael Schumacher, Hamilton, Pastor Maldonado and Nico Hulkenberg.
Nico Rosberg came to the fore, taking the fight to the Bulls. However, he was still 1.5s behind Webber, although only a tenth adrift of Vettel. Fernando Alonso, though, did succeed in splitting the Bulls, taking second place. Rosberg quickly took it off the Ferrari driver.
Vitaly Petrov complained to his team about the new durable hard compound tyres, saying "the tyres are like ice." That's never good. Game over for Maldonado who went off the track at Turn 13 and beached his FW32 in the gravel. He lost control as he came through the 90-mile per hour chicane and just couldn't find any grip to stop himself.
There was little in the way of improving times as the drivers focused on race-pace, putting in the miles in preparation for Sunday's 66-lap grand prix. Vettel was the first of the top ten to improve his time, narrowing the gap to Webber to a second.
However, no one was able to surpass the Aussie, who finished the session in first place with his 1:25.142. Vettel was a second adrift with Rosberg a further two-tenths off the pace.
Times
01. Mark Webber Red Bull-Renault 1m25.142s 27 laps
02. Sebastian Vettel Red Bull-Renault 1m26.149s + 1.007 20 laps
03. Nico Rosberg Mercedes 1m26.379s + 1.237 29 laps
04. Fernando Alonso Ferrari 1m26.480s + 1.338 27 laps
05. Sergio Perez Sauber-Ferrari 1m26.738s + 1.596 26 laps
06. Lewis Hamilton McLaren-Mercedes 1m26.988s + 1.846 19 laps
07. Michael Schumacher Mercedes 1m27.016s + 1.874 32 laps
08. Nick Heidfeld Renault 1m27.132s + 1.990 21 laps
09. Jenson Button McLaren-Mercedes 1m27.138s + 1.996 22 laps
10. Rubens Barrichello Williams-Cosworth 1m27.212s + 2.070 20 laps
11. Vitaly Petrov Renault 1m27.241s + 2.099 22 laps
12. Daniel Ricciardo Toro Rosso-Ferrari 1m27.471s + 2.329 23 laps
13. Pastor Maldonado Williams-Cosworth 1m28.005s + 2.863 11 laps
14. Nico Hulkenberg Force India-Mercedes 1m28.027s + 2.885 26 laps
15. Adrian Sutil Force India-Mercedes 1m28.163s + 3.021 22 laps
16. Felipe Massa Ferrari 1m28.654s + 3.512 28 laps
17. Kamui Kobayashi Sauber-Ferrari 1m28.819s + 3.677 23 laps
18. Jaime Alguersuari Toro Rosso-Ferrari 1m28.995s + 3.853 9 laps
19. Heikki Kovalainen Lotus-Renault 1m29.231s + 4.089 21 laps
20. Jerome D'Ambrosio Virgin-Cosworth 1m30.896s + 5.754 18 laps
21. Timo Glock Virgin-Cosworth 1m31.235s + 6.093 24 laps
22. Tonio Liuzzi HRT-Cosworth 1m31.268s + 6.126 23 laps
23. Jarno Trulli Lotus-Renault 1m31.418s + 6.276 12 laps
24. Narain Karthikeyan HRT-Cosworth 1m32.106s + 6.964 25 laps
