Nico Rosberg continued his great form to set the pace in final practice, which was red flagged for Felipe Massa and Romain Grosjean.
Just past the halfway stage of Saturday's final practice in Monaco, the Ferrari driver had a massive accident when his F138's throttle appeared to stick.
Massa slammed into the barriers at Sainte Devote before heading nose first in the next set. He walked to the medical centre where he was given the all-clear.
However, he wasn't the only red flag as the session ended two minutes early when Grosjean crashed at Sainte Devote, his third incident of the weekend.
With no sign of the expected rain, Esteban Gutierrez got proceedings underway with a 1:26.137, roughly ten seconds slower than the frontrunners at the end of Thursday's second practice. The Mexican rookie, who has yet to score a point, continued lapping and lowered the benchmark time to a 1:17.716 on his eighth lap.
20 minutes into the session the Sauber rookie was overhauled by Nico Hulkenberg and Jean-Eric Vergne as more drivers ventured out get their morning's work underway.
Sebastian Vettel was the next to lead the way, putting in fastest times in the first and second sectors to put together a 1:15.791. Pastor Maldonado jumped to second before Mark Webber made it a Red Bull 1-2, half a second down on his team-mate.
Romain Grosjean, the only driver to crash on Thursday, had another incident before the halfway point as he tagged the barrier at the exit of the tunnel with his left rear tyre as he turned into the chicane. He limped back to the pits.
Halfway through the session the top six were: Vettel, Nico Rosberg, Webber, Pastor Maldonado, Fernando Alonso and Paul di Resta.
Felipe Massa was the next driver into the barriers as he slammed into the barriers at St Devote with the front left of the car as it appeared as if the throttle stuck. He then went head first into the next barrier. The Brazilian walked away a bit gingerly with his F138 very badly damaged. Only the rear right of the car wasn't totalled.
The session restarted only for Adrian Sutil to join the list of crashers as he wall at the Massenet with the rear right of his Force India, forcing the car to swing round and slap it again with the front before sliding along.
Grosjean, out on the supersofts, hit the front with a 1:15.051 but that was soon eclipsed by Rosberg as the German put in three purple sector times on his way to a 1:14.378. Vettel tried to catch the German and was quickest in the first sector but traffic meant he gave up on the lap.
Setting himself up for his next, the reigning World Champ was blocked by red flags as Grosjean again crashed. Coming past the pit exit he dived inside, way too close to Hamilton who was exiting, and then ran it wide, hitting the barriers. Game over.
So the session ended with Rosberg quickest ahead of Grosjean and Vettel.
01. Nico Rosberg Mercedes 1:14.378s 22 laps
02. Romain Grosjean Lotus 1:15.039s +0.661 13 laps
03. Sebastian Vettel Red Bull 1:15.261s +0.883 17 laps
04. Fernando Alonso Ferrari 1:15.286s +0.908 17 laps
05. Lewis Hamilton Mercedes 1:15.311s +0.933 20 laps
06. Kimi Raikkonen Lotus 1:15.380s +1.002 19 laps
07. Mark Webber Red Bull 1:15.550s +1.172 20 laps
08. Paul di Resta Force India 1:15.594s +1.216 17 laps
09. Pastor Maldonado Williams 1:15.861s +1.483 15 laps
10. Nico Hulkenberg Sauber 1:15.926s +1.548 25 laps
11. Sergio Perez McLaren 1:15.958s +1.580 23 laps
12. Jenson Button McLaren 1:15.976s +1.598 19 laps
13. Jean-Eric Vergne Toro Rosso 1:15.976s +1.598 21 laps
14. Daniel Ricciardo Toro Rosso 1:16.060s +1.682 16 laps
15. Adrian Sutil Force India 1:16.068s +1.690 12 laps
16. Felipe Massa Ferrari 1:16.105s +1.727 8 laps
17. Esteban Gutierrez Sauber 1:16.427s +2.049 26 laps
18. Valtteri Bottas Williams 1:16.933s +2.555 17 laps
19. Charles Pic Caterham 1:17.902s +3.524 20 laps
20. Giedo van der Garde Caterham 1:18.102s +3.724 20 laps
21. Jules Bianchi Marussia 1:18.706s +4.328 22 laps
22. Max Chilton Marussia 1:19.228s +4.850 22 laps