When Glen Jackson's last-gasp penalty attempt from wide right floated just past its target, London Irish were relieved and Saracens further frustrated. However, both sides, although still in touch with the Guinness Premiership play-offs race, have much to do if a season's promise is to be realised.

Irish, of course, are the happier of the two. Unbeaten in 2008, this was a seventh win on the trot in all competitions and, although Delon Armitage suffered a knee injury, they have a clutch of sidelined internationals, including Shane Geraghty and Peter Richards, ready to add fresh impetus during the coming weeks.

Despite being irritated by Dave Pearson's refereeing of the breakdown, Irish showed that a combination of grunt up front and speed of foot out wide can create opportunities. Topsy Ojo's slicing midfield break and wonderful long pass set up Sailosi Tagicakibau's try and Peter Hewat is settling in well at full back. The Australian landed six of his seven kicks at goal and put Gonzalo Tiesi away to the posts with a lovely inside pass.

Saracens, determined enough here, require a spark of inspiration. The return of Andy Farrell and Kevin Sorrell to provide a focus in the centre - their injuries may even clear in time for this coming weekend's crucial game against Sale Sharks - will bring much-needed on-field leadership.

It did not help Saracens that a virus ruled out Chris Jack, the All Black lock and lineout specialist, hours before the game, but they have to start producing more than just the flashes of quality that brought a close-range try for Paul Gustard and a late score in the left corner by Kameli Ratuvou.

With home Heineken Cup quarter-final ties to look forward to in early April, against Ospreys and Perpignan respectively, Saracens and Irish must find some extra gears.

Scorers: London Irish: Tries: Tagicakibau (54min), Tiesi (58); Conversion: Hewat. Penalty goals: Hewat 5 (9, 13, 25, 34, 72). Saracens: Tries: Gustard (40), Ratuvou (78). Conversion: Jackson. Penalty goals: Jackson 4 (6, 27, 48, 64).

Scoring sequence (London Irish first): 0-3, 3-3, 6-3, 9-3, 9-6, 12-6, 12-13 (half-time), 12-16, 17-16, 24-16, 24-19, 27-19, 27-24.

London Irish: P Hewat; T Ojo, D Armitage (rep: G Tiesi, 41), S Mapusua, S Tagicakibau; M Catt, P Hodgson; T Lea'aetoa (rep: R Skuse, 55), D Paice, F Rautenbach (rep: D Murphy, 41), N Kennedy, B Casey, K Roche (rep: D Danaher, 50), S Armitage, R Thorpe.

Saracens: D Scarbrough; R Haughton (rep: K Ratuvou, 55), F Leonelli (rep: B Russell, 60), A Powell, R Penney; G Jackson, N de Kock; N Lloyd, F Ongaro (rep: A Kyriacou, 60), C Visagie (rep: C Johnston, 25-35, 55), K Chesney (sin-bin, 24-34), H Vyvyan, P Gustard, D Seymour (rep: T Ryder, 77), B Skirving.

Referee: D Pearson.

Attendance: 8,290.