Irish outscored the cherry and whites three tries to two but the superb kicking of Freddie Burns saw the West Country side claim the four points.
Irish led 22 9 with half an hour remaining only to be clawed back by a resilient Gloucester side who finished strong.
Irish made a dream start to the match turning over the ball from the opening kick-off. Darren Allinson marshalled his forwards around the park with Paice, Garvey and Evans all carrying well. When space was eventually created Allinson passed to Humphreys who fed a great pass to Tagicakibau who glided through the visitors defence before diving over for the opening try. Humphreys added the extras to put Irish 7-0 ahead after four minutes.
Freddie Burns put Gloucester on the board after 6 minutes with a straightforward penalty goal.
Irish dominated the remainder of the opening quarter and should have added a second try. The backs and forwards combined well to put Irish on the front foot and created an overlap out wide, however the final pass failed to go to hand and Irish let the opportunity go.
Ian Humphreys kicked a penalty goal on 25 minutes to put Irish out 10 points to 3.
Gloucester took their chances when on offer and were within four points on the 34 minute mark with Burns kicking his second penalty goal. Irish led 10-6 at the break.
Gloucester started the second half in the ascendancy and Freddie Burns kicked his third penalty goal to put them within a point.
Irish needed a response and duly got one when Halani Aulika, the most prolific tighthead in England this season, powered his way over for Irish’s second score.
Things got better for the Exiles when a Freddie Burns kick parried off two London Irish players and into the hands of Anthony Watson who sprinted 60 metres to score.
London Irish old boy, Dan Murphy got one back for Gloucester from a yard out before the visitors took the lead with a Freddie Burns try and conversion. With 20 minutes left it was a one point game.
Burns kicked a further two penalties to put Gloucester seven points in front with seven minutes left to play. Irish dominated this period but were unable to cross for the crucial score. Gloucester won 29 points to 22.
Irish travel to Kingsholm next Saturday to take on Gloucester in the fourth round of the Amlin Challenge Cup.
Score sequence (London Irish first): 7-0, 7-3, 10-3, 10-6, 10-9, 17-9, 22-9, 22-16, 22-23, 22-26, 22-29
Scorers: London Irish: Tries: Tagicakibau (3), Aulika (45), Watson (48); Conversions: Humphreys (2); Penalties: Humphreys (25); Gloucester: Penalties: Burns (6, 34, 43, 69, 73); Tries: Murphy (55); Burns (60); Conversions; Burns (2)
London Irish team
15. Tom Homer; 14. Topsy Ojo; 13. Jonathan Joseph; 12. Sailosi Tagicakibau (rep: Guy Armitage, 55); 11. Anthony Watson; 10. Ian Humphreys (rep: Shane Geraghty, 71); 9. Darren Allinson (rep: Jack Moates, 65); 1. Max Lahiff (rep: Jerry Yanuyanutawa, 55); 2. David Paice (rep: Scott Lawson, 55); 3. Halani Aulika (rep: Leo Halavatau, 55); 4. Bryn Evans; 5. Matt Garvey (rep: Kieran Low, 61); 6. Declan Danaher (Captain)(rep: Kieran Low, 18-24); 7.Jamie Gibson; 8. Ofisa Treviranus (rep: Chris Hala’ufia, 52)
Replacements: 16. Scott Lawson; 17.Jerry Yanuyanutawa; 18.Leo Halavatau; 19. Kieran Low; 20. Chris Hala’ufia; 21. Guy Armitage; 22. Shane Geraghty; 23. Jack Moates
15. Martyn Thomas (rep: Rob Cook, 40); 14. Charlie Sharples; 13. Tim Molenaar; 12. Freddie Burns; 11. Shane Monahan; 10. Tim Taylor (rep: Mike Tindall, 53); 9. Dan Robson (rep: Dave Lewis, 62); 1. Nick Wood (rep: Dan Murphy, 49); 2. Darren Dawiduik ; 3. Shaun Knight (rep: Rupert Harden, 49); 4. Tom Savage; 5. Jim Hamilton (Captain); 6. Sione Kalamafoni; 7. Matt Cox; 8. Gareth Evans (rep: Ben Morgan, 49)
Replacements: 16. Yann Thomas; 17. Dan Murphy; 18. Rupert Harden; 19. Will James; 20. Ben Morgan; 21. Dave Lewis; 22. Mike Tindall; 23. Rob Cook
Referee: Dudley Philips
Show your "Exile-Style" and wear it with pride!