Mercedes could do nothing to halt Ricciardo, with second-placed Nico Rosberg coming up two-tenths short and Lewis Hamilton a further tenth adrift. Further technical gremlins - thought to be fuel-pressure related - almost stymied the world champion, who did only one fast lap in Q3 to jump from 10th to third.
Fourth place went to Ferrari’s Sebastian Vettel, followed by Force India’s Nico Hulkenberg, and Kimi Raikkonen - set to lose five grid places after a gearbox change - in the second Ferrari. Toro Rosso’s Carlos Sainz, Force India’s Sergio Perez, Daniil Kvyat in the second Toro Rosso, and McLaren’s Fernando Alonso completed the top ten.
Watch: Onboard with Ricciardo for his pole lap of Monaco
Q1 was only moments old, with drivers still on their out laps, when the Ferrari engine in Felipe Nasr’s Sauber blew up exiting the tunnel, leaving the Brazilian to coast down to the escape road with smoke billowing from the rear end. Out came the red flag, but only for five minutes as the excellent marshals completed a rapid clean-up job.
Hamilton set the early pace before Vettel eased ahead, with Rosberg and Ricciardo in third and fourth, but there was another red flag when Verstappen went over the final exit kerb in the swimming pool section and then impacted with the outer wall at Turn 16, damaging his Red Bull for the second time in a few hours. It transpired that he had hit the inner wall of Turn 15 with his right-front wheel, damaging the track rod and leaving himself a passenger.
That incident hurt Alonso too, whose first lap was ruined. When the session resumed, the Spaniard was the first man out, and he had made the top 10 by the end of the session before he got bumped to 11th by Haas’s Romain Grosjean. But he was safely through to Q2, as was Renault’s Kevin Magnussen, leaving Marcus Ericsson as the first faller for Sauber with 1m 16.299s, just ahead of Jolyon Palmer who redeemed himself with a solid 1m 16.586s in the Renault with the ‘old’ engine.
Rio Haryanto again out-qualified Manor team mate Pascal Wehrlein, both happier with the steering weight on their MR05s after new parts had been flown in to alleviate complaints about heaviness associated with the revised rack needed here to give greater lock.
Q2 belonged to Mercedes. Hamilton smashed his rivals immediately with a brilliant lap of 1m 14.056s, which left him well ahead of Vettel’s 1m 14.318s, Ricciardo’s 1m 14.357s (notably on supersoft tyres, with which he will start the race) and Rosberg’s 1m 14.491s, until right at the end Rosberg aced it with 1m 14.043s.
Alonso also made Q3, but neither Williams nor Haas did. Valtteri Bottas was 11th on 1m 15.273s ahead of Esteban Gutierrez on 1m 15.293s, McLaren’s Jenson Button on 1m 15.352s, Felipe Massa on 1m 15.385s and Romain Grosjean on 1m 15.571s. Magnussen was 16th on 1m 16.058s.
Unbelievably, as Hamilton left the garage at the start of Q3 he stopped before the pit exit complaining of no power, and his Mercedes was wheeled back.
By the time it left again, with six minutes to go, Ricciardo had done a stunning lap of 1m 13.622s to Vettel’s 1m 14.522s, and then Rosberg went second with 1m 13.913s. Could the champion get back in the game?
Ricciardo failed to improve on his second run, but despite brushing the same barrier as Verstappen earlier on, Rosberg squeaked down to 1m 13.791s, but after three slow laps Hamilton nailed it on his last one to jump from 10th to third with 1m 13.942s after a great effort.
Neither Vettel nor Raikkonen improved, leaving them fourth and sixth on the timesheets, but Hulkenberg was another star, grabbing fifth for Force India with 1m 14.726s, as Sainz was Toro Rosso’s faster runner on 1m 14.749s in seventh ahead of Perez on 1m 14.902s. Kvyat’s session fell apart with 1m 15.273s, as Alonso took 10th on 1m 15.363s.
For the first time since Singapore last September there isn’t a Mercedes on pole, and one way or another a great race is in prospect.
Thus the provisional grid will line up: Ricciardo, Rosberg; Hamilton, Vettel; Hulkenberg, Sainz; Perez, Kvyat; Alonso, Bottas; Raikkonen, Gutierrez; Button, Massa; Grosjean, Magnussen; Ericsson, Palmer; Haryanto, Wehrlein; Verstappen, Nasr. It should be noted, however, that Magnussen is under investigation for exiting the pits against a red light.