Two Max Northcote-Green tries could not prevent defeat for London Irish in their Anglo-Welsh Cup opener against Bath at Madejski Stadium.
In a game which swung both ways, Exiles took a 22-20 lead with 20 minutes to play after David Paice and Alex Lewington added to two first-half Northcote-Green scores.
But two successful kicks from the imperious Freddie Burns put the visitors 26-22 ahead and despite a late spell of Irish pressure, they could not force one more score.
Irish do pick up one losing bonus point ahead of their trip to Gloucester, also in this competition, next weekend.
In a bid to try and build some momentum, Nick Kennedy named a strong side for the group opener with the likes of James Marshall, Joe Cokanasiga, Alex Lewington and David Paice all among the starters.
On the flip side, Bath shuffled their pack, handing out a couple of debuts as well as giving minutes to some yet to feature this campaign.
And it was the visitors who got off to a flying start, quickly going 7-0 up with less than five minutes on the clock. Centre Ben Tapuai found space to dart through the centre and score under the posts with Burns comfortably converting.
The game developed into a physical scrap with Bath determined to keep hold of their lead, particularly when the hosts opted to kick for the corner rather than go for goal on the quarter of an hour mark.
But Exiles did get off the mark on 17 minutes when some neat play around the Bath 22 led to Northcote-Green receiving possession and dancing across the line to score.
Bath moved 10-5 ahead midway through the half when Burns wound up a penalty kick from just inside the Irish half and it had the legs to drop between the posts.
Both sides saw big chances to add a try come and go with Joe Cokanasiga just missing Brendan McKibbin in the centre before Darren Atkins looked set to score, only for his offload to be cut out.
London Irish did level the scores at 10-10 heading towards the break when a fine burst and pass from Marshall set Northcote-Green away down the right and he showed power and determination to force his way over the line.
Theo Brophy Clews again missed from the tee and would be taken off kicking duties after the restart.
One man certainly not struggling from the tee was Burns, kicking over another penalty to give the visitors a 13-10 lead at half-time.
But Exiles quickly turned the tables after the restart, going ahead for the first time in the contest when following a spell of pressure after a line-out in the corner, skipper Paice burrowed his way over. McKibbin brilliantly kicked the conversion.
However, back came Bath to restore their advantage. And it came in impressive fashion as the influential Burns’ cross-field kick was gathered in by Levi Davis, under pressure from Marshall, to dot down in the corner.
The game continued to swing both ways and Kennedy’s charges moved ahead again, 22-20 when Lewington brilliantly side-stepped his marker on the wing to reach out and score in the corner.
Two Burns penalties put Bath back ahead and set up a grandstand finale at the Mad Stad.
But Exiles could not muster one last hurrah, knocking the ball on just as they were approaching the Bath 22. But they earned one last chance with a penalty, kicking for the corner but after a long spell of pressure, the visitors turned the ball over and kicked to touch to clinch the 26-22 victory.
LONDON IRISH: Marshall, Cokanasiga, Mulchrone, McLean, Lewington (Tikoirotuma 64), Brophy Clews, McKibbin (Steele 56 (Ransom 68)), Elrington, Paice (c), Du Plessis (Hoskins 58), van der Merwe (Lloyd 70), Paulo, Northcote-Green (Smallbone 53), Cowan, Schatz (Treviranus 53).
Rep not used: Woolstencroft.
Tries: Northcote-Green x2 (17,37), Paice (43), Lewington (58)
Con: McKibbin (43)
BATH: Atkins (Banahan 69), Davis (Atkins 77), James Wilson, Tapuai, Jack Wilson, Burns, Allinson (Green 53), Auterac (Nixon 64), van Vuuren (Walker 64), Lahiff (Vaughan 64), Douglas (Stooke 62), Phillips, Garvey (c), Bayliss, Grant.
Reps: Backhouse, Clark.
Tries: Tapuai (4), Davis (52)
Cons: Burns x2 (5,53)
Pens: Burns x4 (20,40,64,70)
Referee: Ben O’Keefe
Attendance: 4,364
Scoring sequence (Irish first): 0-5, 0-7, 5-7, 5-10, 10-10, 10-13, 15-13, 17-13, 17-18, 17-20, 22-20, 22-23, 22-26.