Harlequins had looked to have claimed the better start of the two sides, with Springbok prop Wilco Louw and centre Lennox Anyanwu making inroads through the Irish defence to set up momentum for bruising inside centre Andre Esterhuizen to dive into the corner for a second-minute score.

However, a knock-on by the South African international denied Quins an early lead and set the tone for a troubling first-half for the home side.

Six minutes later and Quins found themselves down to fourteen men as debutant and new signing Josh Bassett was shown a yellow card for a deliberate knock-on.

Irish made quick work of their one-man advantage, with number eight Fa'aso'o forcing his way over for the first points of the day.

Despite also being reduced to 14 men as lock Rob Simmons was sent his marching orders for a high shot on Quins' fullback Nick David, Irish claimed a second score through openside Ben Donnell, bashing his way over from short-range.

A tough first-half for Quins, trailing 14-0 at the break against their closest rivals.

Eventual Man of the Match Tommy Allan was the man to bring Harlequins back into the fight shortly into the second-half. With halfback partner Danny Care displaying some quick-tap thinking to put the visitors on the back foot, Allan was able to sneak through the Irish defence to claim Quins' first points.

The Italian international added the conversion, but not before Donnell was shown a red card by referee Craig Maxwell-Keys for a high tackle on Joe Marler in the lead-up to the score.

Irish had looked to halt Quins' resurgence with an immediate reply through Ollie Hassell-Collins, finishing in the corner after fast hands from the Irish backline.

With half an hour left on the clock, Quins faced a 21-7 scoreboard as they began to build momentum.

On his 100th appearance, Alex Dombrandt was the man to chip further away at the Irish score, wrestling his way to the line as Quins continued to turn up the temperature on the visitors as they continued to leak penalties in the second half.

With Quins turning the screw on the Irish scrum, that wheeled backwards even with a fresh-legged front row on the field, Quins pushed the advantage and saw the ever-classy Allan glide through the Irish defence untouched to claim his second and Quins' third, drawing the score level at 21 points apiece with his third conversion of the day with 20 minutes left on the clock.

Quins claimed a red card of their own just three minutes after Dombrandt's rallying score, with fullback Nick David sent his marching orders making contact with the head of Irish's Italian centre Luca Morisi. With 17 minutes left both teams were down to 14 for the remainder of the fixture.

Irish had looked to break Harlequin hearts late on, with fly-half Paddy Jackson nailing a 72nd-minute penalty after his pack finally managed to get the better of the Harlequins scrum.

Absolute scenes at The Stoop as Harlequins heaved their way, battered and bruised, to the Irish five-metre line as the mighty Harlequin scrum got back on top of their counterparts on the Irish 22, allowing Allan to kick to touch to set up a driving maul five metres from the Irish line with the clock in the red.

Clinching the winner, reserve hooker George Head graced his return from injury by crashing down over the line for yet another dramatic match-winning score for Quins.

Despite not making his final conversion, Man of the Match Tommy Allan sent the ball into the north stand as Harlequins sealed a 26-24 victory, moving Tabai Matson's side up to third in the table, albeit with Saracens and Sale left to play on Sunday.

A three-week break from the Gallagher Premiership for Harlequins, with the hugely exciting Barbarians fixture on Thursday, November 17 next up. Book your tickets here - https://www.eticketing.co.uk/harlequins

Final score: Harlequins 26-24 London Irish

Harlequins

15. Nick David, 14. Joe Marchant, 13. Lennox Anyanwu (53), 12. Andre Esterhuizen, 11. Josh Bassett, 10. Tommy Allan, 9. Danny Care, 1. Joe Marler, 2. Jack Musk (63), 3. Wilco Louw (63) , 4. George Hammond (77), 5. Irne Herbst, 6. Jack Kenningham, 7. Will Evans (72), 8. Alex Dombrandt

Replacements: 16. George Head (63), 17. Fin Baxter, 18. Simon Kerrod (63), 19. Charlie Matthews (77), 20. Archie White, 21. Lewis Gjaltema, 22. Will Edwards (72), 23. Oscar Beard (53)