Michael Dykes scored a hat-trick on his Premiership debut as London Irish beat 14-man Harlequins in a high-scoring derby to boost their top-four hopes.

Quins, meanwhile, had captain Stephan Lewies sent off in between a penalty try and Tommaso Allan’s effort.

Dykes got his third before Josh Bassett and Dino Lamb gave the visitors hope, but Tom Pearson settled it for Irish.

A fourth win in five Premiership outings sees London Irish move up to seventh in the table, one point behind Harlequins and two adrift of fourth-placed Northampton.

Dykes was handed his chance after Ollie Hassell-Collins was named in England’s squad for the Six Nations, having scored eight tries in 12 Premiership outings this season, and the 21-year-old proved to be the perfect replacement.

Irish made a fast start at the Gtech Community Stadium as number eight Cunningham-Smith rounded off a rolling maul from a line-out in the fourth minute, and soon after Dykes finished a backs move from close range.

Dykes was then sent to the sin-bin for a deliberate knock-on to stop Nick David from crossing, which saw Quins awarded a penalty try, but Irish quickly restored their 14-point lead when Stokes picked up the loose ball following Danny Care’s high kick and the full-back scampered in from outside the 22.

The task facing the visitors was made all the harder when flanker Lewies was shown red on 21 minutes for a dangerous clear-out on Cunningham-Smith at the breakdown, although Allan went over to make it 21-12 after a good break by David.

The Italy fly-half could not add the extras and the Exiles had their fourth when Stokes fed Dykes for his second in the corner on the stroke of half-time.

The winger’s hat-trick was completed following the restart after Ben White capitalised on a gap in the defence, but a break from Andre Esterhuizen helped set up Leicester-bound Bassett to pull one back.

Lamb then stretched over and Allan converted to drag Quins to within 11 points with just over 15 minutes left.

However, a yellow card for prop Joe Marler halted their momentum and Pearson squeezed through a gap to extinguish any chance of a comeback, with Paddy Jackson adding his sixth conversion for a flawless afternoon off the kicking tee.

Quins picked up a bonus point to move level on points with Gloucester and remain just ahead of Irish, but Tabai Matson’s side have now lost their past four Premiership fixtures.

London Irish: Stokes; Cinti, Van Rensburg, Jennings, Dykes; Jackson, White; Goodrick-Clarke, Creevy, Hoskins, Simmons, Coleman, Rogerson (capt), Pearson, Cunningham-South.

Replacements: Willemse, Fischetti, Parker, Ratuniyarawa, Gonzalez, Powell, Morisi, Arundell.

Sin-bin: Dykes (19).

Harlequins: Edwards; David, Beard, Esterhuizen, Bassett; Allan, Care; Marler, Head, Louw, Lamb, Herbst, Lewies (capt), Evans, Lawday.

Replacements: Musk, Baxter, Kerrod, Chisholm, Wallace, Steele, Anyanwu, Hyde.

Sin-bin: Marler (69).

Sent off: Lewies (21).

Referee: Matthew Carley.