Lewis Hamilton
Lewis Hamilton currently leads Nico Rosberg by 20 points in the 2015 Drivers' Championship standings. Getty Images

Mercedes' Lewis Hamilton will start on pole at the Monaco Grand Prix for the very first time on 24 May after the reigning world champion overhauled Nico Rosberg in Q3.

Rosberg, who recorded his first victory of the 2015 season in Barcelona earlier this month and trailed only Ferrari's Sebastian Vettel in the final practice session, set the pace in both Q1 and Q2 before Hamilton recorded a time of 1:15.098 to leapfrog his teammate to start at the front of the grid in what is now his home race.

"It's been a long, long time," Hamilton was quoted as saying by BBC Sport after ending his qualifying frustrations in the principality to continue a successful week in which he finally signed a lucrative new three-year deal with the Silver Arrows.

"I can't express to you how happy I am. It was not the easiest session. There were a lot of things that throw you off your rhythm and I did not have that rhythm until the last couple of laps. I am very, very happy.

"This track is so hard. It is difficult to express how difficult it is. In our session we had some problem with tyres and traffic, it was not easy so it makes it even more special. We had some really bad laps, so it was great."

Rosberg will start second at the Circuit de Monaco, with Vettel third and the Red Bulls of Daniel Ricciardo and Daniil Kvyat in fourth and fifth respectively. Kimi Raikkonen will begin from sixth place but will reportedly not require a new gearbox after colliding with a wall in the morning.

"Didn't have a good weekend so far – I lost touch before the end. I knew Lewis was going quickly and it didn't work out – that's it," Rosberg said after coming off second best to his main rival.

"I didn't see [running behind Lewis] as too much of a problem. I could have improved – we changed the balance as I was suffering understeer, and I was confident it was going to come my way. But it didn't."

While there was yet more success for championship leader Hamilton, meanwhile, fellow Briton Jenson Button was cruelly denied a place in Q3 due to a yellow flag introduced after Rosberg had left the track at turn one. He will have to make do with 12th on the grid.

Fellow McLaren-Honda driver Fernando Alonso is two places behind Button after he suffered a technical failure at St. Devote during Q2.