London Irish turned on the second-half afterburners at Twickenham to complete a 33-16 bonus-point victory and put an early dent in Saracens' Aviva Premiership title hopes.

The Exiles capitalised on the sin-binning of Alex Goode by amassing 15 points, including tries for Delon Armitage and Sailosi Tagicakibau.

Ryan Lamb, who had kicked two penalties in the first half, landed another five points to give Irish a 21-10 lead with 15 minutes to go.

Impressive tries from Ernst Joubert and Schalk Brits saw Saracens control the first half, which they finished 10-6 up, but Irish's play after the interval was clinical.

A penalty try that earned substitute Kevin Barrett a yellow card - the fourth of the match - and a late touch down from Topsy Ojo completed the rout in the final 10 minutes.