Indeed, the Exiles hardly needed to work up a sweat against a shambolic Saracens side who could only muster a single Nicky Little penalty.
Saracens coach Rod Kafer chose to field untried fly-half Ben Russell, and the gamble backfired badly.
The 20-year-old struggled to impose himself on the game, making a succession of poor kicks and missing a couple of tackles. He was eventually put out of his misery at the interval.
But perhaps the novice was dragged down to the standard of those around him in a truly dreadful opening half as both sides kicked possession away with abandon.
Saracens misery was compounded when they lost England flanker Richard Hill to a knee injury shortly before half-time.
Irish, on the other hand, were more enterprising – particularly when they avoided the combative Saracens back row and when wings Bishop and Staniforth got their hands on the ball.
Home fly-half Barry Everitt got the scoreboard moving with a straightforward penalty on the half-hour, awarded after visiting hooker Raphael Ibanez was sin-binned for handling in a ruck.
That was the cue for some concerted Irish pressure and their first try a minute before the break.
The move was started by Mike Catt when he launched a counter-attack from deep and several phases later the overlap was engineered for Justin Bishop to slide into the right-hand corner.
A bleak afternoon for Saracens got worse when Hill was carried off with a injury to his left knee and the World Cup winner did not reappear in the second half.
His side immediately dug themselves into deeper trouble when Simon Raiwalui – only on the field for 10 minutes – earned himself a yellow card for a stamp on Irish No.8 Phil Murphy.
They rallied briefly for Little to pull back three points with his second penalty attempt 11 minutes from time.
But Irish picked up the pace again and struck twice in the last six minutes to make sure of the points.
A cleverly-worked move off the back of a close-range scrum in the 74th minute saw Kieron Dawson spin down the blindside for replacement centre Delon Armitage to slide over in the corner.
Then, as Saracens tried to attack from deep, they lost the ball in midfield for Michael Horak to break a tackle and touch down under the posts with Armitage adding the simple conversion.
For London Irish:Try: Bishop, Armitage, HorakCon: ArmitagePen: Everitt
For Saracens:Pen: Little