Saracens blew a string of scoring chances but still had enough power to overwhelm London Irish today and take a step closer to the Guinness Premiership play-off places.

The hosts claimed an easy win at Vicarage Road with a first-half penalty try and a conversion and four penalties from the boot of fly-half Glen Jackson.

All the Exiles could manage from a deeply disappointing performance was a consolation try two minutes from time by Delon Armitage and a solitary Riki Flutey penalty.

The win moves Saracens above Sale into fifth place - three points behind Wasps and on course for a shot at the title and a place in next season's Heineken Cup.

Irish, by contrast, are in danger of getting sucked into the relegation battle and were flattered by the margin of their defeat as Sarries missed five clear try-scoring chances.

Both sides were missing some big names - with England squad members Andy Farrell and Shane Geraghty sitting the game out, while France flanker Olivier Magne also took a break.

Mike Catt was given the chance to top up his match fitness in midfield for Irish but had his work cut out against a physical home side with an eye on joining the play-off race.

The Exiles actually dominated territory for most of the opening quarter, moving the ball around with Seilala Mapusua and Topsy Ojo threatening to create some openings against a well-organised defence.

But Saracens were more direct and incisive - and might have been out of sight by half-time, with two scores ruled out by the television match official, one more for a foot in touch and one for a forward pass.

They claimed a try with a drive from the line-out which followed Richard Haughton's blast down the right - only for TMO Chris Rees to rule it out - before Jackson stepped up to open the scoring with a straightforward penalty after 18 minutes, to make up for his third-minute miss.

Another video replay decision ruled that Kameli Ratuvou had put a foot in touch diving into the corner, and a third score was wiped off when Kevin Sorrell was denied after a forward pass in the build-up.

Jackson was on target again with a second penalty on 22 minutes to double the lead, and five minutes later Irish could not contain the dominant Saracens pack when referee Dave Pearson awarded a penalty try for pulling round a five-metre scrum.

The only time Irish really gained a foothold in Saracens territory saw Flutey miss the target with a simple penalty shot, and his side had another lucky escape when full-back Dan Scarbrough put a foot in touch delivering what should have been another scoring pass to Kris Chesney.

Jackson, though, made no mistake four minutes before the break - drilling over a 30metre penalty for a comfortable 16-0 lead.

Flutey finally got his team on the board with a penalty seven minutes after the interval. But they were on the back foot again after a superb piece of invention from Jackson who took a short drop-out to himself and launched Haughton, Sorrell and Cencus Johnston on a 70m raid.

With a huge overlap on the left, the only way Irish could stop a certain try was by Nick Kennedy straying offside to kill the ball. The lock was instantly yellow-carded, and Jackson added another three points with his fourth successful penalty.

The game petered out after that, Irish messing up a handful of half-chances before Armitage got over on the left - while Saracens replacement Rodd Penney was sin-binned moments after arriving on the pitch for a shove on the Irish full-back.