If McLaren didn't have enough to worry about after being forced to ditch its version of the 'blown diffuser' after day one of the British Grand Prix, the sight of Sebastian Vettel and Mark Webber again setting the pace at Silverstone would not make things any better.
The German, who won in Valencia last time out to thrust himself back into the championship hunt, narrowly edged his team-mate to claim top spot in the final 60-minute session, while Lewis Hamilton and Jenson Button managed only seventh and twelfth as McLaren attempted to make up for lost time after struggling with its latest developments on Friday. The current points leader, Hamilton was half a second off Vettel's pace, with Button another couple of tenths adrift.
It was not all plain sailing for Red Bull, however, with Vettel suffering a scary moment as he attempted to better his time in the final minute. Approaching the revised Abbey curve, the nose of his RB6 dropped onto the tarmac, the result of an apparent breakage in the mounting. The team set to work investigating the cause on Vettel's return to the pits, but the German's smile suggested it was not a major issue.
Webber, meanwhile, was just 0.034secs behind his team-mate as the pair look set for another pole position battle at the venue where Vettel won last year.
The Red Bull duo had a tenth of a second in hand over their nearest challenger, with Ferrari's Fernando Alonso third fastest, and a couple of tenths over Nico Rosberg and Felipe Massa, who completed the top five. The rest of the field grouped in closely-matched bunches, with sixth-placed Robert Kubica and tenth-placed Rubens Barrichello in the same tenth bracket.
In all, the top 14 drivers were all within a second of Vettel, with only a gearbox-troubled Adrian Sutil, Toro Rosso team-mates Sebastien Buemi and Jaime Alguersuari and the second Force India of Tonio Liuzzi missing out before the newcomer teams - where Virgin's Timo Glock had yet another throttle problem -trailed in over three seconds off the pace.