With two races left in the World Championship triathlon series Olympic bronze medallist Emma Moffatt leads the rankings and Brad Kahlefeldt has moved up to fourth, after a sixth place finish in London on Sunday.

Moffatt had a tough day on Saturday and finished ninth in her race, won by 21-year-old Canadian Paula Findlay on her world championship series debut. However, the Australian now leads the series by 38 points from New Zealand's Andrea Hewitt, who came fourth.

Just six days after an incredible sprint finish to the previous leg in Hamburg, Moffatt was clearly struggling to back up at the Hyde Park circuit - the same track that will be used for the 2012 London Olympics.

The Olympic bronze medallist, just beaten to the line by Sweden's Lisa Norden in Hamburg, admitted that event had taken a lot out of her as a run of 14 successive podium finishes came to an end.

"It (last weekend's race) probably did take its toll," Moffatt said. "I got away with it on the swim and bike, but the girls pushed the pace at the start of the run and I struggled to respond and eventually fell off the back.

"It's up to me now to recover from this week and last week, put in a good block of training and see if I can build back up for the last few races and hold my lead."

Moffatt, still to win a race in this year's series, has 2539 points from Hewitt's 2501 with two events left to run.

Australia's other main hopes were never in contention.

Olympic champion Emma Snowsill, who is yet to find top gear after a long lay-off with injury, again struggled in the opening 1500-metre swim and withdrew from the race soon after.

Erin Densham, the Beijing Olympian who endured heart surgery last year and has since made a measured comeback to feature in her first world championship series start of the year, was an innocent victim in a minor crash during the early stages of the 40km bike leg. She pushed on but eventually withdrew before the run.

Annabel Luxford finished 21st, Felicity Abram 23rd, and Emma Jackson 34th, while Felicity Sheedy-Ryan joined Snowsill and Densham on the sidelines to be one of 15 who did not finish.

Kahlefeldt, who also finished sixth in Hamburg last week, produced a workmanlike display at the London 2012 Olympic course in Hyde Park.

"Brad was exceptionally tough today," Triathlon Australia's head coach Shaun Stephens said.

"He is short on initial speed for the first kilometre out of transition at the moment given his injury five weeks ago.

"Another solid block and some speed in his training and I am confident Brad can get a lot faster for (the grand final in) Budapest."

Spain's Javier Gomez made it two wins in a week when he claimed the race, overcoming the challenge from Britain's Brownlee brothers - Alistair and Jonathan - to power home.

Of the other Australians, Courtney Atkinson finished 50th to slip to ninth in the overall standings while Dan Wilson came in 24th, Brendan Sexton was 33rd and James Seear 49th.

AAP