Gloucester Rugby came alive late in the second half to punish London Welsh as a Mark Atkinson double secured a bonus point victory at the Kassam Stadium.
Welsh had gone toe-to-toe with the Cherry & Whites for much of the game but remain on one Aviva Premiership Rugby point after Taione Vea’s sin bin prompted a collapse.
Atkinson and Jonny May notched three late tries in the space of five minutes, adding to Henry Purdy and Charlie Sharples tries before the break.
But the Exiles went into the interval just two points behind after a Ben Pienaar try had given them real hope.
Dan Robson, Matt Kvesic and Elliott Stooke were all making their first Aviva Premiership Rugby starts of the season for a new-look Gloucester.
Meanwhile, captain Tom May was one of four changes for an Exiles side looking to record their first victory against the Cherry & Whites since 1983.
Olly Barkley – Aviva Premiership Rugby’s third highest points scorer of all time – had the chance to get the Exiles on the board from the off, but his penalty drifted beyond the left-hand post.
Welsh’s tails remained up however thanks to forwards pressure, while Gloucester lost prop Dan Murphy inside the first five minutes after injury.
James Hook did not have any early luck from the tee either, going astray with his own penalty, but Welsh remained the livelier with May and Ollie Stedman making useful gains.
Led by John Afoa and Richard Hibbard, Gloucester were beginning to impose themselves at scrumtime yet Hook, with his second penalty of the night, was again off the mark
But after Welsh rumbled their way through 12 phases downfield, a penalty in the ruck turned into a stunning try for Gloucester just before the half-hour mark.
The ball made its way from Robson to May and despite the England wing slipping after cutting inside, a neat exchange between Billy Twelvetrees and Purdy saw the latter throw himself over the line.
And Gloucester were over the whitewash again a minute later, Hook breaking from deep before spraying the ball out to the lively Robson, who set Sharples away.
This time Wales international Hook was on cue with the conversion, yet the Exiles hard work was rewarded on 35 minutes after Pienaar added the finishing touch to a superb rolling maul from a lineout.
Barkley reduced the arrears to five and after clever work from Piri Weepu at the breakdown, knocked through a simple penalty to reel the Cherry & Whites in heading into half time.
On resumption Gloucester stymied Exiles’ momentum with bruising carries of their own, and a drive by Purdy yielded a penalty.
Billy Twelvetrees took over kicking duties to thump through before another effort crashed against the upright moments later.
Welsh were continuing to match up with Gloucester but Vea was sin binned for collapsing a scrum on 64 minutes, with replacement Greig Laidlaw duly extending the visitors’ lead to eight from the tee.
And the game was finally up for the hosts after a jinking May squeezed through the line, opening up acres of space for replacement centre Atkinson to finish.
Atkinson then needed no help to tie up proceedings in the last ten minutes – and crucially the bonus point after skating through the centre from deep, before May ran onto a chip to notch a deserved score.
And the Cherry & Whites heaped further misery on their hosts with a penalty try at the death.