A second-half comeback saw Gloucester win their third game in three in the Challenge Cup this afternoon.
Sailosi Tagicakibau put London Irish ahead early on, after which there were few scoring chances for either side.
The Exiles started the second half well, scoring two tries in the opening 10 minutes through Halani Aulika and Anthony Watson.
Gloucester made a series of changes as they tried to get back in the match, and the substitutions paid off as Dan Murphy ran in a try five minutes after coming on.
Freddie Burns scored Gloucester's second try, and kicked the conversion to put the visitors ahead for the first time in the match.
Burns, who made his England debut last Saturday, kicked two penalties in the last 10 minutes to leave Irish needing a converted try to get back on level terms.
The win sees Gloucester move above London Irish in Pool 1, having won all three of their games so far in the Challenge Cup.
