McLaren's rookie Kevin Magnussen topped the third day of pre-season Formula 1 testing at Jerez as the Mercedes teams continued to dominate.
Magnussen's teammate, Jenson Button, set the pace earlier in the day and his 1m25.030s effort stood until mid-way through the afternoon. But after three red flags – caused by Fernando Alonso's Ferrari, Daniel Ricciardo's Red Bull and the Force India of Nico Hulkenberg – Lewis Hamilton moved to the top for Mercedes.
The 2008 world champion's 1m23.952s lap was the quickest of the week so far, surpassing Button's day two best, but another red flag almost immediately halted proceedings again after Adrian Sutil crashed his Sauber approaching Turn 7. After a fifth stoppage, for Jean-Eric Vergne's stranded Toro Rosso, there was around 40 minutes left of the session.
Magnussen, who had only taken over from Button with two and half hours of running remaining, then went out on Pirelli's medium tire. He set two laps good enough to topple Hamilton, the best being 1m23.276s.
Williams continued its fine testing form with second, Felipe Massa setting a 1m23.700s in the closing minutes to also move ahead of Hamilton.
With Fernando Alonso's best on mediums, set early in the afternoon, only being 1m25.495s, it meant the top four drivers were all Mercedes powered. Once again, the German marque also looked good in terms of mileage, Hamilton covering 62 laps, while McLaren's MP4-29 managed 92 with Button's and Magnussen's stints combined.
Force India struggled to get many laps in, Hulkenberg only completing 17 between issues, but a late run allowed him to claim sixth-fastest time.