Heikki Kovalainen brought the curtain down early on the opening practice session for the Monaco Grand Prix in spectacular fashion.
With nine minutes remaining of the hour-and-a-half event around the streets of the principality, the Renault engine in the Finn's Caterham decided to give way.
Worse still it did so as Kovalainen hurtled through the tunnel, filling the space under the Fairmont hotel with clouds of white smoke.
Kovalainen finally came to a halt on the short straight emerging out of the tunnel down to the Port Chicane, forcing an immediate red flag.
Given the poor visibility in the tunnel, it was soon decided to call a halt on the session at the end of which Fernando Alonso in his Ferrari emerged at the head of another congested field.
Alonso, joint leader in the standings alongside reigning champion Sebastian Vettel, finished with a lap of one minute 16.263 seconds.
Given the time there is plenty of margin for improvement bearing in mind Vettel's pole lap from last year was 2.7secs quicker.
Lotus' Romain Grosjean led the way for most and at various stages of the session, but was forced to settle for second best behind Alonso, finishing 0.365s adrift.
On a contrasting morning for Lotus, Kimi Raikkonen endured frustration as a steering issue confined him to the garage for all but one installation lap, leaving him without a time.
Sauber's Sergio Perez, back on track here a year after suffering a frightening accident that left him in hospital for two days and forced him out of two races, was third overall.
The Mexican, along with McLaren's Lewis Hamilton - now a Monaco resident - and race-winner last time out in Spain in Pastor Maldonado in his Williams, all finished just under half a second down, with the trio covered by 0.049.
Ferrari's Felipe Massa, with the pressure on him this weekend to perform, finished reasonably close to team-mate Alonso for once, the Brazilian sixth on the timesheet, 0.578 off the pace.
Kamui Kobayashi was next up in the second Sauber, followed by McLaren's Jenson Button, Vettel in his Red Bull and Mercedes' of Nico Rosberg to round out the top 10, all covered by one second.
Seven-times champion Michael Schumacher, who will serve a five-place grid penalty on Sunday for running into the back of Bruno Senna in his Williams in Spain, was 1.148 down in 11th.
Red Bull's Mark Webber, winner here two years ago, was 13th, with Force India's Paul di Resta 16th, two seconds down, and notably 0.7 off team-mate Nico Hulkenberg who was 12th.
Times
01 Fernando Alonso Ferrari 1:16.265 22 laps
02 Romain Grosjean Lotus 1:16.630 0.365 17 laps
03 Sergio Perez Sauber 1:16.711 0.446 19 laps
04 Lewis Hamilton McLaren 1:16.747 0.482 12 laps
05 Pastor Maldonado Williams 1:16.760 0.495 20 laps
06 Felipe Massa Ferrari 1:16.843 0.578 19 laps
07 Kamui Kobayashi Sauber 1:17.038 0.773 21 laps
08 Jenson Button McLaren 1:17.190 0.925 13 laps
09 Sebastian Vettel Red Bull 1:17.222 0.957 14 laps
10 Nico Rosberg Mercedes 1:17.261 0.996 18 laps
11 Michael Schumacher Mercedes 1:17.413 1.148 14 laps
12 Nico Hulkenberg Force India 1:17.631 1.366 18 laps
13 Mark Webber Red Bull 1:18.106 1.841 14 laps
14 Jean-Eric Vergne Toro Rosso 1:18.209 1.944 25 laps
15 Daniel Ricciardo Toro Rosso 1:18.252 1.987 28 laps
16 Paul di Resta Force India 1:18.302 2.037 16 laps
17 Bruno Senna Williams 1:18.617 2.352 20 laps
18 Heikki Kovalainen Caterham 1:19.039 2.774 20 laps
19 Vitaly Petrov Caterham 1:19.341 3.076 16 laps
20 Narain Karthikeyan HRT 1:20.838 4.573 26 laps
21 Charles Pic Marussia 1:20.895 4.630 18 laps
22 Timo Glock Marussia 1:21.638 5.373 9 laps
23 Pedro de la Rosa HRT 1:22.423 6.158 15 laps
Kimi Raikkonen Lotus 1 laps
