Alistair and Jonny Brownlee occupied the top two places at the ITU World Triathlon in Kitzbuhel.
Alistair suffered an Achilles injury in February which had forced him to miss a number of races, with Sunday's event being his first at elite level since winning his second world title in China in September.
The 24-year-old had feared his chances of competing at the Olympics in London had been scuppered by the injury but he reasserted his claim to be the gold medal favourite.
Alistair was four seconds adrift of the lead and two behind Jonny after the swim but he soon made that time up and although there was little to choose between the pair, the former produced the only sub 30-minute run and ultimately won comfortably in one hour 50 minutes 13 seconds for his third victory in Kitzbuhel in four years.
Jonny was second in 1hr 51mins 02secs, 16 secs ahead of Javier Gomez of Spain while David McNamee was ninth and Aaron Harris 18th.