World championship leader Verstappen was just over 0.204s down on the time that had put Alonso on provisional pole after two sectors of his lap, but produced a stunning finish to edge out the Aston Martin by 0.084s.

In claiming a first pole position in eight appearances at Formula 1's most famous circuit, Red Bull's Verstappen denied Alonso his first pole since 2012.

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Verstappen's team-mate - and nearest title challenger - Sergio Perez, will start from the back of the grid after crashing out in Q1 at Saint Devote, leaving the Dutchman responsible for extending Red Bull's streak of five wins to start the season.

Charles Leclerc, who has taken pole for the previous two years at his home circuit, finished third for Ferrari, but was later demoted to sixth after incurring a three-place grid penalty for impeding McLaren's Lando Norris.

As a result, Alpine's Esteban Ocon is reward for his stunning lap is a third-place start, with Leclerc's team-mate Carlos Sainz jumping to fourth.

Lewis Hamilton was the other beneficiary from Leclerc's penalty and will start fifth after producing a strong final lap in his upgraded Mercedes, having earlier only just scraped through Q1 and Q2.

Pierre Gasly completed a strong Alpine display to take seventh ahead of Hamilton's team-mate George Russell, while Yuki Tsunoda was ninth for AlphaTauri.

Norris rounded out the top 10, having made it through to the final part of qualifying despite crashing in the closing stages of Q2.

Monaco GP Qualifying Result
1) Max Verstappen, Red Bull
2) Fernando Alonso, Aston Martin
3) Esteban Ocon, Alpine
4) Carlos Sainz, Ferrari
5) Lewis Hamilton, Mercedes
6) Charles Leclerc, Ferrari*
7) Pierre Gasly, Alpine
8) George Russell, Mercedes
9) Yuki Tsunoda, AlphaTauri
10) Lando Norris, McLaren

*Leclerc was demoted three places for impeding Norris in in Q3

Verstappen triumphs in 'best qualifying session ever'

The session had been billed as the most important qualifying of the season, but few could have imagined the drama that was delivered across 70 minutes on the streets of Monaco.

There had been speculation coming into the weekend that there could be a four-team fight for pole position, and that did turn out to be the case, albeit with Alpine unexpectedly crashing the party.

It became clear across the session that track evolution, and getting out at the right moment, would prove a crucial factor.

After some sparring to start Q3, there was a pause for breath as the contenders pitted for fresh tyres for the final stages, after which a stunning finale began.

Ocon momentarily allowed Alpine to dream, as he produced a brilliant lap to dislodge Verstappen from the top of the timesheet, but Leclerc would narrowly beat his time moments later.

Then came Alonso, seeking to build on a brilliant start to the season which has seen him claim four podiums in five races for Aston Martin, with a lap that saw him take ownership of top spot.

That left Verstappen as the only real threat, and the Dutchman's wait for a pole in his adopted hometown looked set to be extended as he trailed by two tenths after an uninspiring first couple of sectors.

However, risking it all as he chucked his car around the final corners, making contact with the barriers on multiple occasions, Verstappen produced an inspired performance to make up almost three tenths.

"It was a bit tricky for me in the first two sectors in Q3, the tyres were a bit too cold, with the out-lap and a lot of traffic, I couldn't do it the way I wanted to," Verstappen told Sky Sports F1.

"From there onwards, I just tried to risk it more and more. I came out of Turn 12 and I was like, 'I need to go to flat out, we might end up in the wall or not!' I pushed a few barriers, right and left, but luckily it worked out for us."

While Monaco's place on the F1 calendar has been questioned by some due to the difficulty of overtaking on a Sunday, this was a finale that reminded anyone with doubt about the circuit of the unique form of magic it is capable of creating.

Sky Sports F1's Jenson Button summed it up, when he said: "For me, that was the best qualifying session I've ever watched."

Perez crash, Hamilton struggles create early drama

Button's high praise for Saturday's show factored in a frantic first two parts to qualifying, which also produced dramatic endings on the ever-improving track.

Before any of that, Perez played his part in an ensuring the rest of the field will start in a Red Bull sandwich, with the Mexican left in 20th after a barely explicable crash.

Perez had appeared to be capable of challenging Verstappen for pole after finishing narrowly behind his team-mate in final practice, which made it all the more surprising that he would make an error in Q1, where he had plenty of margin to advance.

The only explanation for the incident was that Perez was distracted by an Alpine emerging from the pit lane as he entered Sainte Devote, but it was a total loss of control that looks set to ensure his 14-point deficit to Verstappen is significantly increased on Sunday.

While Perez's contact with the barrier was terminal, most others were flirting with danger as just about every car on the track appeared to be grazing the circuit's walls.

Hamilton was among those pushing the limits, and after a reasonably positive Friday in Mercedes' heavily updated W14, he suddenly was at major risk of a Q1 exit.

The seven-time world champion ruined what was intended to be his final flying lap as he sat in the drop zone, but was fortunate to still have time to go again after an error at the Nouvelle Chicane, and took full advantage to sneak through.

He wasn't alone, with Sainz also only progressing at the final moment, while Haas duo Kevin Magnussen and Nico Hulkenberg joined Zhou Guanyu and Logan Sargeant in making early exits.

Hamilton was again the main protagonist in Q2, following a similar pattern to Q1 before once more coming through in the closing moments, but there was no such recovery for Alonso's Aston Martin team-mate Lance Stroll, who will start from 14th.

Norris, who appeared on for a strong result after finishing fifth in second and third practice, appeared to have spurned his chance for a high starting position when he struck the barrier at Tabac in the closing stages of Q2.

The Brit had already done enough to reach Q3, and was indebted to his mechanics after their stunningly fast repair job put him in a position to be held up by Leclerc in the closing moments of the session.

Sky Sports F1's live Monaco GP schedule

Sunday May 28
7.15am: F3 Feature Race
8.45am: F2 Feature Race
12.30pm: Grand Prix Sunday Monaco GP build-up
2pm: THE MONACO GRAND PRIX
4pm: Chequered Flag Monaco GP reaction
5pm: Ted's Notebook
5.30pm: The 107th Indy 500

Watch the Monaco Grand Prix live on Sky Sports F1 on Sunday with build-up from 12.30pm and lights out at 2pm. Get Sky Sports