Leicester took advantage of an ill-disciplined London Irish display to win a Premiership thriller by one point.
Irish led most of the first half after Paddy Jackson's first-minute try but the hosts came in level at the break.
Trailing 23-18, the Exiles had Terrence Hepetema sent off for leading with the shoulder in a head-high tackle.
Kini Murimurivalu dived over to seal victory for Tigers but a penalty try and last-gasp Matt Cornish score saw the visitors snatch two bonus points.
The win lifts Steve Borthwick's Leicester up to eighth before Saturday's matches, closing the gap to sixth-placed Irish to three points.
The Exiles gave away 20 penalties at Mattioli Woods Welford Road - the most by any side in the Premiership this season - with captain Matt Rogerson yellow-carded for a high tackle, which was mitigated down from a red card, in the first half.
Jackson was sent over after just 37 seconds after Hepetema got between two Tigers tacklers to offload to the fly-half, with Kobus van Wyk ghosting in under the posts from a fine Zack Henry pass for the hosts.
Leicester led for the first time after the interval, half-time replacement Ollie Chessum crashing over out wide from the base of a ruck, before Irish had tries of their own ruled out for an unnecessary obstruction from Hepetema and a Nick Phipps knock-on.
Declan Kidney's side did finally get their reward, Ollie Hassell-Collins scoring in the corner after a steady maul, but Hepetema was then red-carded for avoidable contact to the head of Van Wyk, which could lead to a hefty suspension.
Murimurivalu put the Tigers 33-18 up thanks to a magnificent bit of play from Jack van Poortvliet, who was then sin-binned for a deliberate knock-on which resulted in a penalty try for Irish.
The home side finished the game with 13 men as Joe Heyes was shown a yellow for a high tackle and well after the 80-minute mark Cornish drove over to earn the gutsy Exiles losing bonus and try bonus points.
Tigers head coach Steve Borthwick told BBC Radio Leicester:
"We're pleased with the result and the players showed a lot of resilience and composure, but we're disappointed with the first 20 and the last 20 minutes.
"We have high expectations. We left points out on the pitch and let them score too easily. Last season we won 29 points, this season we have 28 already - that's progress.
"The aspect of the performance I was most pleased with was that we started poorly, they were 10-3 up. We hadn't been in the game but the players stuck at it. We built pressure, came in at 13-all. That was as bad as we'd played first 20 and we were still in the game."
Leicester Tigers: Steward; Van Wyk, Moroni, Scott, Porter; Henry, Wigglesworth; De Bruin, T Youngs (capt), Cole, Green, Lavanini, Wells, Reffell, Brink.
Replacements: Clare, Leatigaga, Heyes, Chessum, Wallace, Van Poortvliet, McPhillips, Murimurivalu.
London Irish: Parton; Loader, Rona, Hepetema, Hassell-Collins; Jackson, Phipps; Goodrick-Clarke, Creevy, Chawatama, Mafi, Simmons, Rogerson (capt), Cowan, Tuisue.
Replacements: Cornish, Dell, Hoskins, Munga, Nott, Donnell, Meehan, Joseph.
Referee: Wayne Barnes (RFU).