Sebastian Vettel was the surprise pace-setter in Saturday's final practice for the Monaco GP as he beat the Merc duo on the supersofts.
Having covered almost 100 laps on the soft tyres on Thursday morning, Mercedes opted to head out on the supersoft tyres at the start of FP3, a different strategy to all the other teams.
Using the option rubber, Lewis Hamilton went flying through on a 1:19.074, comfortably quicker than the chasing pack on the soft tyres.
A spate of purples for the World Champion saw him drop his benchmark time to a 1:17.504 then a 1:17.021 and finally a 1:16.705.
Nico Rosberg lined up second, 0.566s down on his team-mate while Kimi Raikkonen was the fastest of the soft tyre runners in the opening 20 minutes but he was 1.3s down.
Swapping to the supersofts, the Ferrari driver closed the gap to 0.696s only to hit the barrier at Sainte Devote with the left side of his SF15-T. Raikkonen report that he had "punctured the tyre instantly" but it did appear as if the impact broke the car's rear suspension.
The session was briefly red flagged as the marshals moved his car out of the way, resuming two minutes later.
Sebastian Vettel took the fight to the Mercedes drivers as he used the supersoft tyres to climb up to second place, 0.180s down, while Max Verstappen joined Raikkonen in the barriers.
Having just put in his best time of the morning, he slapped the wall at the final corner with the rear of his STR10 but was able to drive back to the pits with a damaged rear wing.
The final ten minutes saw the drivers again head out on the supersoft tyres, this time with minimal fuel on board.
Rosberg improved to second but that became third as Vettel went quickest of all with a 1:16.143. Rosberg put in another lap to take second, 0.218s down on his compatriot, while Hamilton finished the practice unhappy with his Mercedes.
Daniel Ricciardo was fourth for Red Bull Racing ahead of Carlos Sainz and Raikkonen.
Jenson Button, Verstappen and Romain Grosjean completed the top ten.
1 Sebastian Vettel Ferrari 1:16.143 28 laps
2 Nico Rosberg Mercedes 1:16.361 0.218 32 laps
3 Lewis Hamilton Mercedes 1:16.705 0.562 32 laps
4 Daniel Ricciardo Red Bull 1:17.120 0.977 27 laps
5 Carlos Sainz Toro Rosso 1:17.256 1.113 40 laps
6 Kimi Raikkonen Ferrari 1:17.401 1.258 11 laps
7 Daniil Kvyat Red Bull 1:17.471 1.328 29 laps
8 Jenson Button McLaren 1:17.767 1.624 29 laps
9 Max Verstappen Toro Rosso 1:17.788 1.645 24 laps
10 Romain Grosjean Lotus 1:17.806 1.663 29 laps
11 Sergio Perez Force India 1:17.832 1.689 31 laps
12 Pastor Maldonado Lotus 1:17.956 1.813 29 laps
13 Nico Hulkenberg Force India 1:18.102 1.959 33 laps
14 Fernando Alonso McLaren 1:18.197 2.054 27 laps
15 Valtteri Bottas Williams 1:18.212 2.069 30 laps
16 Felipe Massa Williams 1:18.242 2.099 33 laps
17 Felipe Nasr Sauber 1:18.767 2.624 39 laps
18 Marcus Ericsson Sauber 1:19.269 3.126 38 laps
19 Will Stevens Manor 1:21.093 4.950 32 laps
20 Roberto Merhi Manor 1:22.225 6.082 31 laps