Gloucester narrowly beat London Irish thanks to a Billy Twelvetrees penalty in added time that dented the Exiles' hopes of a top six finish.
Both sides traded three tries apiece in an entertaining first half as London Irish led 25-19 at the interval.
A more cagey second half saw Gloucester edge ahead after Louis Rees-Zammit's try and Twelvetrees' first penalty following a Rob Simmons sin-binning.
Paddy Jackson's penalty put Irish 28-27 up before Twelvetrees' three points.
Gloucester climb to 10th while a losing bonus point leaves Irish seventh with two games to play. Sixth-placed Leicester, who are on the same number of points, face bottom-of-the-table Worcester on Saturday.
Results elsewhere over the weekend could see Declan Kidney's side slip to as low as ninth.
Irish had the chance to close out the match in the final minute but conceded a penalty on Gloucester's 22-metre line when not releasing before the Cherry and Whites secured an advantage from the following attacking line-out that set up Twelvetrees' winning shot at goal.
The lead had changed hands four times in the first half as Irish led first through Curtis Rona before Santiago Carreras and Willi Heinz went over in quick succession in reply.
Will Goodrick-Clarke edged Irish back ahead with their second but Gloucester lead again through full-back Kyle Moyle. Albert Tuisue finished off the first half scoring with a third London Irish try that handed them a six-point lead.
Australia lock Simmons was sent to the sin-bin on the hour for a high tackle on Gloucester hooker Jack Singleton and Wales winger Rees-Zammit went over from the resulting penalty to bring the hosts within a point.
Twelvetrees missed that conversion attempt to reclaim the lead but he would make no mistake from his next two efforts off the tee, which ultimately proved decisive.
Gloucester head coach George Skivington told BBC Radio Gloucestershire:
"I expected it to be a close contest, we're not a million miles apart in the league and we're two teams that are building nicely.
"In the first half we had a lot of good moments but gave away some silly penalties and field position. I thought our discipline was better in the second half.
"I didn't think we were clinical enough but in the end we dogged it out and executed really well after winning those two last penalties.
"You need big players and strong personalities in moments like that and Billy certainly took his chance.
"There's plenty of bits and pieces for us to work on, but I think there's more trust now in the system and there's glimpses of what we're trying to build in attack."
Gloucester: Moyle; Rees-Zammit, Harris, Atkinson, Carreras; Twelvetrees, Heinz; Rapava-Ruskin, Singleton, Balmain, Slater, Craig, Ackermann, Ludlow (capt), Morgan.
Replacements: Socino, Ford-Robinson, Stanley, Garvey, Clarke, Varney, Evans, Thorley.
London Irish: Parton; Stokes, Rona, P Cokanasiga, Hassell-Collins; Jackson, Groom; Goodrick-Clarke, Creevy, Chawatama, Nott, Simmons, Rogerson (capt), Donnell, Tuisue.
Replacements: Matu'u, Gigena, Hoskins, Coleman, O'Brien, Englefield, Atkins, Hepetema.
Sin-bin: Simmons (49 mins).
Referee: Matthew Carley.