GB's Jonny Brownlee and Helen Jenkins win in San Diego

Jonny Brownlee completed a British double by winning the San Diego World Triathlon Series.

He followed up Helen Jenkins's triumph on Friday with his first Olympic distance victory in the world series.

The 22-year-old beat Switzerland's Sven Riederer by five seconds, with South African Richard Murray third.

"I didn't know what to expect. Seven months is a long time out," said Brownlee, who had already qualified for London 2012.

"I was in a bit of shock at the race briefing, thinking 'wow, it's been a long, long time since I've been in one of these'.

"I went into the race very relaxed because I knew I didn't have to do anything. I didn't have to finish top nine, top four or anything - I just had to race my own race. I was pleased."

Brownlee - favourite for victory in the absence of elder brother and reigning world champion Alistair who is recovering from an Achilles injury - controlled the race throughout.

He spent much of the 1.5km swim and 40km bike section in the front group, and never relinquished the lead he opened up early in the 10km run as he strolled over the line in one hour, 48 minutes and 47 seconds.

Tim Don, who is fighting for the final Great Britain spot in the Olympic team, finished seventh, with Will Clarke 20th, David McNamee 23rd and Adam Bowden 37th. Aaron Harris and Todd Leckie did not finish.

Defending world champion Jenkins consolidated her position as favourite for Olympic gold with an impressive performance 24 hours earlier.

The Welsh athlete, 28, ran clear of Australian Erin Densham in the closing 10km run after being part of an eight-woman breakaway on the 40km bike ride.

"It was a good race. I had to work hard for that," Jenkins said.

"I really pushed the swim and we really worked hard on the bike and that was hard all the way," added Jenkins, who won silver behind Densham in the opening race of the series in Sydney.

"I really enjoyed the run course. It was really cool. There was so many people out there supporting - it was awesome."

Jenkins won in a time of 1:58:21, more than a minute ahead of Densham.

Vicky Holland was the next best-placed Briton in fifth, behind America's Laura Bennett and France's Jessica Harrison.

Liz Blatchford came home in 16th, with fellow British athletes Non Stanford (21) Lois Rosindale (30), Vanessa Raw (37) and Jodie Stimpson (45) further down the field.

The athletes travel to Madrid for the next round of the World Triathlon Series on 26-27 May.