Lewis Hamilton went quickest in free practice for the Monaco Grand in an incident-packed first session that ended under red flags when a loose drain cover damaged the cars of Nico Rosberg and Jenson Button.

Mercedes were early adopters of the new ultrasoft tyre in the session and Hamilton quickly took charge of the timesheet on the purple-banded tyre and he eventually worked his way down to a best time of 1:15.537 halfway through the session.

Rosberg got to a tenth off that pace but in the closing minutes of the session, as he exited Ste Devote, he ran over a drain cover on the exit of the corner with the piece of metal puncturing his rear left tyre.

The cover was then kicked back onto the circuit and into the path of Jenson Button. The front right of his McLaren collided with the object and he too sustained a puncture and front wing damage. The session was swiftly red-flagged and repairs to the cover began. There would be no restart.

The incident was one of many in the session. The first came just 25 minutes in the session when Williams’ Felipe Massa lost control on the entry to Ste Dvote. The rear left side of his car smacked into the barriers and the recovery crane swung into action.

Renault’s Jolyon Palmer also made contact with the barriers. The Briton went wide at Tabac and damaged the right rear suspension of his car. He pulled over at the Swimming Pool where his session ended.  

A number of drivers had near misses during the session. Valterri Bottas appeared to loose control in the tunnel before rescuing the situation and Esteban Gutierrez also displayed good car control on the run down to the Nouvelle Chicane catching his car when it was unbalanced on the exit from the tunnel. The Haas driver’s session came to an early halt however when he was forced to pull over with a power unit issue.

With Hamilton quickest ahead of Rosberg, third place in the session went to Sebastian Vettel who took his Ferrari to within half a second of Hamilton. Daniel Ricciardo, using an upgraded Renault engine for the first time here, was fourth, seven tenths of a second off the best time of the session.

Spanish Grand Prix winner Max Verstappen was firth fastest with a time of 1:16.371, just five hundredths of a second clear of the man he replaced at Red Bull Racing, Daniil Kvyat.

Seventh place went to Force India’s Nico Hulkenberg, who finished ahead of team-mate Sergio Perez, the second Ferrari of Kimi Raikkonen and Toro Rosso’s Carlos Sainz.

2016 Monaco Grand Prix – Free Practice 1
1 Lewis Hamilton Mercedes 1:15.537
2 Nico Rosberg Mercedes 1:15.638s 0.101
3 Sebastian Vettel Ferrari 1:15.956s 0.419
4 Daniel Ricciardo Red Bull 1:16.308s 0.771
5 Max Verstappen Red Bull 1:16.371s 0.834
6 Daniil Kvyat Toro Rosso 1:16.426s 0.889
7 Nico Hulkenberg Force India 1:16.560s 1.023
8 Sergio Perez Force India 1:16.697s 1.160
9 Kimi Raikkonen Ferrari 1:16.912s 1.375
10 Carlos Sainz Toro Rosso 1:17.130s 1.593
11 Valtteri Bottas Williams 1:17.562s 2.025
12 Romain Grosjean Haas 1:17.599s 2.062
13 Fernando Alonso McLaren 1:17.838s 2.301
14 Esteban Gutierrez Haas 1:17.909s 2.372
15 Jenson Button McLaren 1:17.920s 2.383
16 Felipe Nasr Sauber 1:18.187s 2.650
17 Kevin Magnussen Renault 1:18.274s 2.737
18 Marcus Ericsson Sauber 1:18.301s 2.764
19 Felipe Massa Williams 1:18.746s 3.209
20 Jolyon Palmer Renault 1:18.871s 3.334
21 Rio Haryanto Manor 1:20.528s 4.991
22 Pascal Wehrlein Manor 1:20.868s 5.331