London Irish booked themselves a semi-final play off trip to Welford Road to play Leicester, thanks to a hard-earned win over Saracens at the Madejski Stadium.

Irish could not produce the sort of free-flowing attacking rugby that saw them run in nine tries against Wasps last weekend, but the intent was there from both sides to attack and the result was a thoroughly entertaining game of rugby.

Irish scored tries through Delon Armitage (2) and Topsy Ojo (2) and Saracens responded with scores from Dan Harris and Thomas Castaignede, in a game that also saw four players yellow carded.

The game marked the end of the illustrious career of Saracens scrum-half Kyran Bracken, and while the World Cup winner will be disappointed with the 30-18 final score, he will at least take comfort from the fact Sarries finished the season looking a completely different outfit to the one that started it.

Brian Smith's Irish side, unquestionably the surprise package of this year's Guinness Premiership, will travel to Leicester as underdogs while knowing they have the pace and power to seriously trouble the Tigers.

In an end-to-end game, Sarries opened the scoring with a well-worked try that saw second-row Simon Raiwalui take advantage of a lapse in concentration by Riki Flutey to charge through a gap before feeding centre Harris to score. Glen Jackson's conversion made it 7-0 after five minutes.

The former Waikato fly-half added another penalty in the 12th minute before Irish got on the scoreboard with a terrific try of the own five minutes later.

Prop Richard Skuse collected a loose ball in space on the halfway line and timed his pass perfectly to Armitage who showed electric pace to ghost outside the Saracens' defence and

score in the corner.

Flutey was unable to convert and Jackson kept the Irish at bay with his second penalty of the afternoon making the score 13-5 after 24 minutes.

Flutey knocked over a penalty of his own before the home side lost number eight Juan Leguizamon to the sin bin for a cynical shirt pull on Castaignede as the Frenchman looked odds-on to gather his own chip and score under the posts.

Sarries were unable to take advantage of the Argentinian's absence however, and it was Irish who struck when Armitage capitalised on some superb vision by Flutey to hack the ball downfield and win the foot race to score his second. Flutey's conversion took Irish ahead for the first time, and they went further in front when the impressive Ojo read Jackson's pass to score an interception try. Flutey added the extras to make it 22-13 after 35 minutes.

Sarries were further hampered when they lost Raiwalui to the bin in the 39th minute, just as Leguizamon returned to the field.

However, Sarries kept themselves in the game just after the break when Castaignede carved open the home side's defence with a beautifully-angled run to the line after Irish had coughed up possession on halfway.

Saracens lost Tom Ryder to the sin bin for killing the ball on the floor before Bracken also departed the field for the last time in the 50th minute, to a richly-deserved standing ovation.

Substitute Barry Everitt stretched the Irish lead to seven points with a 61st minute penalty as both sides continued to play a high-risk brand of rugby.

Nick Kennedy was carded for Irish with 15 minutes left as the game became increasingly tetchy and Ojo closed the game in the dying minutes with his second interception of the game.