Harlequins earned London bragging rights as a four-try show against London Irish hauled Dean Richards' men to within touching distance of a shock play-off place.

Quins' quartet of David Strettle, Stuart Abbott, Paul Volley and Mike Brown gave England boss Brian Ashton a timely nudge with tries as the home side ended a three-game losing run.

New Zealand fly-half Andrew Mehrtens made his first start since New Year's Day and in the pack England international Nick Easter failed to recover from a neck injury.

It was the Kiwi who struck first, slotting home a simple penalty after the visitors were penalised at a ruck.

Although Barry Everitt quickly responded with a penalty of his own, Mehrtens nudged the home side back in front with another three points.

After a quiet opening Harlequins produced a breathless 10-minute burst midway through the half to open up a sizeable lead.

Firstly, a bull-dozing run from forward Chris Hala'ufia allowed England international Abbott to stride clear only for Andy Gomarsall to knock on with the line at his mercy.

Gomarsall quickly made amends taking a quick tap penalty and, after six phases on the Irish line, Quins skipper Paul Volley burrowed over with Mehrtens converting.

Moments later and a break from Mike Brown took the ball into the Exiles 22 and quickly recycled ball allowed the Quins full-back to crash over in the corner. Mehrtens again converted.

As half-time approached Irish threw themselves a lifeline when Sailosi Tagicakibau broke a couple of tackles to set Riki Flutey free to cross the line and Everitt's conversion dragged the Exiles back into contention.

Any hopes the visitors may have had of an unlikely comeback were quickly dispelled by two rapid Quins tries at the start of the second half.

Hala'ufia once again broke the gain-line and smooth passing allowed England flyer Strettle to dart over unopposed in the corner, with Mehrtens again adding the extras.

For Strettle it was the winger's eighth league try of a hugely successful season.

Before the Exiles had a chance to draw breath they fell further behind when Mehrtens delivered a superbly timed pass, allowing centre Abbott to stroll over.

With the contest seemingly decided, both sides decided to ring the changes and while the substitutions came thick and fast the on-field action stalled.

As Quins took their foot off the gas, Irish staged a late rally and were rewarded for their efforts with a consolation effort.

Numerous phases in the Harlequins 22 stretched the home defence and flanker Kieran Roche broke the line to score but it was too little too late as London Irish slumped to a second league defeat in seven.