Oliver Mytton won Oxford Tri Club's championship after a strong finish.
Mytton, Crispin Hetherington and Matthew Rowley were all in with a shout of victory, going into the run.
But Mytton raced clear to beat Hetherington by 26 seconds on a course centred around Cassington Lake.
Mytton clocked 1hr 33mins 38secs in the 1,100m swim, 19-mile cycle and four-mile run event.
Rowley finished third in 1.35.09, while Ruth Burnett won the women's event over the same course in 1.42.12.
Burnett was followed by Sarah Kerswell (1.50.28) and Sarah Mead (1.53.24).
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here