Lewis Hamilton is aiming to reel off his third successive win and to consolidate his grip on this year's title race at this weekend's 65th running of the Monaco Grand Prix.
The defending four-time world champion, fresh from victories in Azerbaijan and Spain, arrives in the Mediterranean principality with a 17-point lead on nearest rival and fellow-four-time champion Sebastian Vettel of Ferrari.
But in an unpredictable season punctuated by unexpected dramas, the 33-year-old Briton knows he faces a challenge to stay on top on the unforgiving barrier-lined streets.
"We have worked very hard as a team to get into this position, but we know this is a major task," Hamilton said. "It is going to be a close fight and I am excited by the prospect of this race."
Vettel won last year's race, ending a four-year run of Mercedes domination at a track where qualifying is of paramount importance due to the difficulty in overtaking during the race.
Vettel is looking for his third Monaco win on Sunday, and as the German bids to bounce back, after leading the championship earlier in the season, he and Hamilton both fear a major challenge from Red Bull Racing who will be celebrating their 250th race start.
They won both their 100th and 150th races and Dutchman Max Verstappen believes they should be making a major impact this weekend.
"The team has worked hard and I feel we should be really competitive this time," he said.
Hamilton and Mercedes are expecting Red Bull to be a threat.
"It is going to be a serious challenge," Hamilton said. "The others are going to be hard to beat. If you look at Daniel Ricciardo, in Spain, he was much quicker in the last sector and the last sector is all down-force, so they're going to be rapid in Monaco, and very hard to beat.
"Montreal as well, where it's very, very hard to get temperature into the tyres, it's going to be multiple laps of driving to get temperatures into those tyres there.
"So different things that are coming up are challenging, I don't think it's going to be as clear as it was at every single race."