The Mercedes of Nico Rosberg and Lewis Hamilton were second and third fastest, both within six-tenths of a second of Vettel, followed by Red Bull’s Daniel Ricciardo, Toro Rosso’s Carlos Sainz, and the luckless Raikkonen.
Max Verstappen was the only other driver to make significant contact with the barriers, taking a rear wing endplate off his Toro Rosso after losing the back end through the final Anthony Noghes turn.
Mercedes ran their session back to front; they began on the supersoft tyres and switched to softs, just as everyone else bar Marussia did the opposite. Rosberg and Hamilton then made further runs on the supersofts as Ferrari’s speed became apparent.
Hamilton had set the pace from the get-go, getting down to 1m 16.705s. But towards the end Vettel homed in on that with 1m 16.885s, before landing his masterstroke of 1m 16.143s.
Rosberg had struggled initially, with a best of 1m 16.770s leaving him 0.065s shy of his team mate after several efforts to go quicker. Hamilton, meanwhile, was equalling but not bettering his time when he went back on to the supersofts, complaining that he had less grip than he had before; he was told that his tyre temperatures were to blame.
Eventually Rosberg screwed out a 1m 16.361s to go second, but was still 0.218s off Vettel; Hamilton had a scruffy end to his session, trapped in traffic and thus unable to push really hard, and ended up 0.562s off Vettel’s time. It seems that Mercedes have some further set-up work to do before qualifying.
Ricciardo took fourth with 1m 17.120s for Red Bull, just under a second off the pace, then came the impressive Sainz with 1m 17.256s for Toro Rosso.
Lots of drivers - Hamilton, Sainz and Marcus Ericsson (twice), Daniil Kvyat, Vettel, Romain Grosjean and Valtteri Bottas - overshot the chicane, while Ericsson and Pastor Maldonado separately ventured into the escape road at Sainte Devote. But it was Raikkonen who brought out the red flag for four minutes, 27 minutes in, when he got the back end out going into Sainte Devote just after going third fastest with 1m 17.401s and punctured his Ferrari’s left-rear supersoft tyre.
Later, Hamilton made a great catch when his Mercedes almost got away from him approaching the chicane. Just before the final 15 minutes, Verstappen backed his Toro Rosso into the wall having moved up to sixth with 1m 17.788s.
Raikkonen’s time held up for sixth, ahead of Kvyat on 1m 17.471s and a happy Jenson Button who jumped to eighth for McLaren with 1m 17.767s. Verstappen’s time left him a solid ninth as Grosjean completed the top 10 with 1m 17.806s in the Lotus. Sergio Perez took 11th for Force India with 1m 17.832s despite a near miss with a slowing Vettel in Rascasse at the end, and Maldonado was the final sub-1m 18s runner with 1m 17.956s.
Nico Hulkenberg was 13th on 1m 18.102s for Force India from McLaren's Fernando Alonso on 1m 18.197s, and Williams’ tough weekend continued as Valtteri Bottas couldn’t better 1m 18.212s and Felipe Massa was stuck with 1m 18.242s.
Sauber, too, continued to struggle; Felipe Nasr’s best was 1m 18.767s, Ericsson’s 1m 19.269s.
At the back, Will Stevens yet again avoided making any mistakes on his way to 1m 21.093s for Marussia, as Roberto Merhi overshot the chicane and later went over the rumble strips in the Swimming Pool letting Bottas through. The Spaniard brought up the rear with 1m 22.225s.
Thus the scene is set for a dramatic shootout for pole between the Ferrari and Mercedes drivers in a qualifying session that many believe is every bit as crucial - perhaps even more so - than the race itself.
