No doubt given an extra boost by his maiden F1 victory in China last weekend, Nico Rosberg posted the fastest time of day one in Bahrain to lead the pack by four-tenths of a second in his Mercedes. While the majority of his rivals were completing longer runs, the German banged in a 1min 32.816secs effort that not only vaulted him to the head of the timesheets but proved good enough to keep him there as the rest switched to qualifying-style runs in the latter stages of the 90-minute session. Rosberg and Mercedes had conducted a lot of their race simulation work in FP1, and used the softer tyre to good effect as he underlined the W03\'s potential over a short run. McLaren was among those concentrating on race runs, and never made a play to challenge Rosberg, who toppled Lewis Hamilton from P1 with his flying effort. The Woking team did not even break into the afternoon\'s top three, and therefore the same positions overall, as Hamilton and team-mate Jenson Button were made do with fourth and sixth, either side of the second Mercedes of Michael Schumacher, after failing to find sufficient pace on the softer Pirellis. In their stead, Red Bull took both advantage and heart from second and third places, with Sebastian Vettel backing up his more promising morning performance with what looked wet to be second spot until team-mate Mark Webber went a couple of tenths faster. The German has reverted to the newer RBR exhaust set-up this weekend, and proved to be a top three regular throughout the day. Schumacher appeared to be held up on what would have been his fastest lap on the option tyre, and was then unable to reconstruct the performance as the softer rubber dropped off quickly on the abrasive BIC surface. Tyre wear and lack of grip proved to be a universal concern, with the soft Pirellis particularly susceptible. Behind Button, Kamui Kobayashi continued Sauber\'s strong recent run, backed up by Sergio Perez in tenths, the pair sandwiching Fernando Alonso - looking a little happier with his Ferrari - and Romain Grosjean at the foot of the top ten. While Daniel Ricciardo made amends for a disappointing FP1 time with eleventh place on the second session timesheets, Felipe Massa will also take heart from an improved run on a circuit he loves to take twelfth, one spot ahead of the second Lotus of Kimi Raikkonen. Jean-Eric Vergne also underlined a different approach from Toro Rosso by taking 14th in the session, ahead of both Williams drivers, who found themselves split by the two Caterhams as Bruno Senna attempted to make up for having had to hand over his car to reserve Valtteri Bottas in FP1. His mood won\'t have been helped by the fact the young Finn is listed a couple of places above him on the combined sheets after lapping fully seven-tenths faster. The FP2 order was further confused by the absence of both Force India drivers, after the Silverstone-based team opted to withdraw from the session and complete its preparation for FP3 in order to make the return trip to their hotels before darkness descends. Spooked by a close call with a Molotov Cocktail on Wednesday, the team is taking a sensitive approach to its workforce\'s safety concerns, but insists it will take part in both qualifying and the race over the weekend. Paul di Resta and Nico Hulkenberg finished third and sixth respectively in FP1 and their times were still good enough for sixth and eighth on the combined lists. Others to set better times in the first session included Hamilton, who remained fourth overall; Raikkonen, who appears eleventh on the combined times; Maldonado and Bottas and rookie Charles Pic. Practice continues with an hour of running on Saturday morning, before the business of qualifying gets underway after lunch.