With three different drivers topping the sheets in the three practice sessions today's qualifying - not to mention tomorrow's race - was always going to be something of a conundrum.

Throw into the mix the ever increasing temperatures, the dustiness of the track, the technical problems befalling certain drivers, the unexplained lack of pace of others and the ongoing confusion over the 2012 Pirellis and you have the making of a real thriller.

Surprisingly, this morning didn't witness the red hot finish we'd expected. When the drivers did switch from the medium to soft rubber in the final fifteen minutes there were few really significant improvements. While Button, the Lotus and Force India duos showed real pace, in the Englishman's case against his current run of form, Hamilton, the Red Bulls, Ferrari and Mercedes were largely disappointing.

Being the street circuit that it is, pole here will be as important as it is at Monaco, pity then poor Mark Webber who was sidelined with a technical problem this morning and has therefore yet to complete any mileage on the softer rubber.

With seven winners from the first eight races, many are wondering whether an eight name will be added to the list tomorrow, while others speculate as to who might become the first man to win two races.

One man being tipped as a potential eighth winner is Michael Schumacher, while either of the Lotus drivers has to be worth a punt.

After a number of visits here, Valencia, as a race track, remains as unattractive and unfulfilling as ever, it adds nothing to the experience of the driver or the fan and the sooner it is dropped the better.

Twenty minutes before the start of the session, Marussia boss John Booth reveals that Timo Glock's stomach bug and that the German could miss qualifying. Bob Constanduros subsequently tweets that the Marussia has left the circuit. The Russian team subsequently confirms that Timo is a no-show.

Air temperature is 26 degrees C and the track temperature 43 degrees, the hottest it has been all weekend, though it will get hotter over the next hour.

The lights go green for Q1 and Ricciardo leads the way, followed by Maldonado, Senna, Pic, Webber, Alonso and Massa. Surprising to see some of the big guns out so early, not so in the Australian's case.

As Ricciardo posts 40.707, all but Vettel, Button, Hamilton, Kovalainen, Petrov and de la Rosa are on track.

Senna posts 40.468 as Perez locks up going into T2. Massa takes the top spot with a 39.634 as Raikkonen goes second and di Resta third. A 40.211 sees Grosjean go fourth ahead of Senna and Ricciardo.

Webber heads back to the pits as everybody bar Vettel continues.