Nico Rosberg topped an action-packed hour of final practice that saw three big crashes involving Felipe Massa, Adrian Sutil and Romain Grosjean.
Rosberg continued to display impressive pace, lapping his Mercedes 0.661s faster than anyone else, although Sebastian Vettel's quick lap was ruined by traffic at the swimming pool that left him third fastest overall. Grosjean was second quickest but had his second crash at St Devote of the weekend when he overcooked the entry to the first corner with just a minute left on the clock.
The rear of the Lotus got out of shape before the apex and Grosjean could do nothing to stop it slamming into the barriers, rotating the front left and front wing into the wall as well. Once again the Lotus mechanics will have to piece together the car, but at least have the added incentive of knowing it is in contention for a good grid slot in the afternoon.
Massa clouted the outside wall on the entrance to St Devote, wiping the front left wheel off its wishbones, decimating the front wing and damaging the left rear. The rebounding Ferrari then skidded down to the run off area where the next set of barriers finished off the other two corners of the car. The reason for the crash is unknown, but the way he locked both fronts under braking while trying to turn in hinted at some kind of issue with the car rather than pure driver error. Either way, the mechanics from Maranello face a monster job to get the car back in one piece ahead of qualifying and Massa did not get an opportunity to try the super-softs in FP3.
Sutil provided a little less work for Force India over the lunch break but still managed to wipe the front right wheel off his car when he slammed into the barriers at Beau Rivage. He had lost the rear of the car at the top of the hill and then struggled to control a tank slapper before hitting the wall.
The Massa and Grosjean incidents brought out red flags but Sutil's wreckage was dealt with swiftly by the marshals under yellow flags.
Of the cars that finished the final practice hour in one piece, few look capable of challenging Rosberg for pole position if it stays dry, with Ferrari's Fernando Alonso and Mercedes' team-mate Lewis Hamilton nearly a second adrift in fourth and fifth. However, a clean lap without traffic is crucial to a fast time and with only ten cars on track in Q3 they will likely have a better chance of hooking up all three sectors.
Kimi Raikkonen was sixth fastest and not immune to the odd mistake as he had to use the run-off at Mirabeau after locking up his fronts on a hot lap. Mark Webber was seventh fastest ahead of Paul di Resta and a heroic effort by Pastor Maldonado to drag his recalcitrant Williams into the top ten. Nico Hulkenberg was tenth fastest ahead of the two McLarens, led by Sergio Perez.
Neither Sutil nor Massa completed a lap on the super-soft tyres before their accidents, which explains their lowly finishing positions.