LEWIS Hamilton is not getting carried away with his first Monaco pole position, rejecting the notion that victory is all but assured today.

This is shaping up to be quite the week for the reigning Formula One world champion. Hamilton signed a lucrative, three-year contract extension with Mercedes on Wednesday and followed it up with an impressive day of practice and a Saturday to savour.

The 30-year-old endured a topsy-turvy time in the final practice session and first two sections of qualifying, but produced a blistering lap of one minute 15.098 seconds in Q3 to secure his maiden F1 pole on the streets of Monte Carlo.

"It's been a long, long time," Hamilton said. "I can't express just how happy I am. I didn't have the rhythm until the last two laps, so I was really, really happy with it and coming across the line just hoping for once that you've got it.

"This is incredibly special for me and for my guys, who have worked so hard this weekend, so I'm very, very happy."

Hamilton pipped Mercedes team-mate Nico Rosberg by 0.342 seconds, meaning a third straight Monaco win may now be beyond the German. Of the last 11 races here, 10 have been won by the driver starting in pole, with the only exception Hamilton's victory from third during his title-winning season of 2008.

Perhaps that is why the British driver was so quick to swat away suggestions that today will be a cakewalk.

"The job is not even half done," Hamilton said. "There's so much to do...many, many laps here. It's going to be mentally and physically challenging."

Challenging it may be, but odds of 1/5 on him to win highlight that few expect Hamilton to come a cropper - although not even victory would represent the "perfect weekend" he spoke of last week.

Hamilton said: "The pole and the win is a pretty good weekend, but naturally a perfect weekend is when you ace every session. It is not so far off that and naturally tomorrow is the day."

Mercedes team-mate Rosberg is aware the odds are stacked against him, but is hoping his victory in Spain last time out will act as inspiration.

"I lost the good rhythm at the end, which is a shame," said the driver already 20 points behind Hamilton in the championship standings. "Lewis did a good job today, unfortunately now it's getting really difficult to win this race. But I will dream tonight of my Barcelona start and hope to have another one tomorrow."

That will be one of Rosberg's few opportunities to jump ahead of Hamilton in Monaco's narrow streets and, despite the potential for disaster, Mercedes' head of motorsport Toto Wolff will not be ordering his drivers to rein it in.

"We let them race," he said. "Obviously Monaco is very different, you end up in the barrier or in the wars, much quicker. But both of them know how crucial the championship is and this race is crucial.

"We haven't seen any incidents recently, so there is no need to really call for team orders or interfere in the racing."

Sebastian Vettel starts third on the grid, while Red Bull's improvements were shown by Daniel Ricciardo and Daniil Kvyat following the Ferrari driver.

McLaren's hopes of a first point of the season have been boosted by the penalties given to Toro Rosso's Carlos Sainz Jr and Romain Grosjean of Lotus. It means Jenson Button will start 10th on the grid, with Fernando Alonso in 13th.