Ahead of today's all important qualifying session for the Monaco Grand Prix, the air temperature is 23 degrees C, while the track temperature is 45 degrees. It is bright, sunny and quite beautiful.

Fernando Alonso was quickest in this morning's session, as he was on Friday, however, the session was marred by two hefty crashes - one involving Nico Rosberg the other Tonio Liuzzi - which meant we lost 18 minutes of tracktime.

Liuzzi's crash, coming at the very end of the session, meant that neither Red Bull driver got to do a flying lap on the supersoft option rubber. Consequently, it would appear that the Milton Keynes duo have something in reserve.

Over the years Monaco has produced some surprises, however, it is unlikely that the weather or lack of fuel will decide tomorrow's winner. On the other hand, tyre strategy could play a major part in deciding the finishing order, as it has in most races this season.

Pirelli reckons the supersofts are 1.2s - 1.4s quicker than the softs however, they are only good for 2 hot laps. On the other hand, the softs are said to be good for 30 laps which means we could be seeing a number of drivers opt for just one stop here.

As ever, traffic is a nightmare here and even if Rosberg and Liuzzi don't make it Q1 there will be 22 cars out there and could still be a lottery with some of the big names paying the price.

With overtaking nigh impossible here tomorrow, despite KERS and DRS, pole position here is more important that at any other circuit, with the pole-sitter usually heading off into the distance unchallenged. The big question is who can stop the Vettel/Red Bull steamroller, because this is going to be one of the best opportunities.

As the lights go green Rosberg stands at the back of the Mercedes garage, helmet on and ready to go. However, his mechanics are still working feverishly on his car.

Petrov and D'Ambrosio get the session underway, followed by Schumacher, a five-time winner here.

D'Ambrosio posts a 1:23.192 enjoying a moment of glory at the top of the Monaco timesheets before Petrov posts 18.112 and Schumacher 18.176. Elsewhere, Rosberg climbs into his car.

Heidfeld goes third, ahead of Sutil, Buemi, Perez and Alguersuari.

Button goes straight to the top of the timesheets (17.059) having gone quickest in the two final sectors. Next time around he immediately goes quicker in S1. As the Englishman continues on his way, teammate Hamilton posts 16.321 to go quickest. Button re-takes the top sot with a 15.969 having been quickest in all three sectors. All these times posted on the harder (prime) rubber.

As Schumacher improves with a 16.910, Vettel goes quickest in S2, finally crossing the line at 16.317 to go second overall.

A 15.606 sees Vettel go quickest as teammate Webber consolidates seventh with a 16.985. Moments later Button sticks in a 15.397 the 2009 champion looking very, very good this weekend. If it is down to tyres, Jense is your man.

With 9:40 on the clock, Rosberg leaves the pits. Only the Hispania duo haven't post a time, both having failed to make the 107% rule cut in any of the practice sessions.

Hamilton posts 15.207 to make it a McLaren 1-2, as Rosberg immediately goes fifth with a 16.265, his first flying lap of the day. Superb stuff from the youngster.

Other than the Hispanias, the Virgins and Lotus fill the danger zone with Buemi keeping them company. The Swiss makes the surprise decision to switch to the option rubber, playing his cards mighty early. Sutil, di Resta and Perez hovering above the danger zone.

Buemi improves to seventh with a 16.358 as Schumacher opts to make the switch to supersofts - a big gamble from the German.

Perez (option) goes sixth with a 16.115 as Schumacher fails to improve, the German bogged down in traffic. As Alguersuari clouts the back of Kobayashi's Sauber as the two round Rascasse.

Schumacher improves to sixth with a 16.092 as teammate Rosberg, now on the softer rubber, posts 15.858.

Hamilton, Button, Vettel and Alonso remain in their cars, happy with what they've done. Alguersuari looks as though he'll miss the cut, the Spaniard in the pits following his collision.