And only three kilometres into the race, eyebrows were raised when McKiernan opened up a five-metre gap which by the finishing line had stretched to almost 200m ahead of fourth-placed O'Sullivan.

In her first competition around the tough Phoenix Park circuit since finishing fourth in December's European Cross Country Championships, O'Sullivan looked a shadow of the athlete who scored a runaway 2003 victory.

In contrast McKiernan was a class act as she defied strong, gusting winds to steer herself to a solid victory in 33 minutes and 39 seconds.

McKiernan was well clear of runner-up Elana Fadeeva who clocked 33mins 50secs, and Analia Rosa in third who was a further 12 seconds down on the Ukrainian.

Then came a relaxed looking O'Sullivan, waving to the crowds as she finished fourth behind the Portuguese runner, well shy of her 32:24 course record in a time of 34:16.

"I felt fine, but with the kind of training I have done, there is nowhere I was ready for a 10K race at the moment," said the unperturbed O'Sullivan.

"I didn't really want to get too involved in the race, this was more of a training run than anything else.

"Next week is when the Olympic preparations and really hard work will start," O'Sullivan reassured concerned supporters as she prepares to fly to the United States tomorrow for a month's altitude training.

However, McKiernan, who in the past has been overshadowed by O'Sullivan's magnificent career, was delighted with her victory.

Last year's runner-up said: "Obviously it's great to win here, although the conditions made it very tough for me. I think it's a couple of years ago since I last beat Sonia.

"Clearly she was not at her best today and I don't know how her winter's training has gone. But I'm sure she'll be back and doing everything right during the summer."

McKiernan's assessment of her Irish team mate was echoed by Australian star, Craig Mottram who successfully defended his men's title.

The wind slowed him to a winning time of 29:11, but Mottram's performance was nevertheless a world class run, as he finished 50 seconds ahead of Portugal's Victor Almeida who in turn had three seconds to spare on Northern Ireland's Andy Graffin.

"Don't read too much into how Sonia ran," said Mottram, who has been O'Sullivan's constant training partner since their elite Aussie group arrived in London just over a month ago.

"She knows what she was doing and was aware she wasn't quite ready for a race like this," said the World Cup 3,000m champion.

"I'm sure you'll find when she gets to America and starts preparing seriously for the Olympics, everything will be okay," said Mottram.

O'Sullivan's coach and partner Nic Bideau is already at their high altitude 6,000 feet Laguna Mountain venue near San Diego, with other squad members including World Cross Country champion Benita Johnson.

Mottram said: "Sonia won't be lacking any support once we are all back together. She's going to be all right and, knowing what training she's done, it would have been stupid for her to have pushed it today."

Results:

Men: 1 C Mottram (Aus) 29min 11sec, 2 V Almeida (Por) 30.01, 3 A Graffin (Nirl) 30.04, 4 G Stewart (Sco) 30.22, 5 I Galan (Spa) 30.27, 6 A Naumov (Ukr) 30.30, 7 A Sitkovsky (Ukr) 30.33, 8 D Donnelly (Nirl) 30.40, 9 D Anderson (England) 30.54, 10 L Novo (Por) 31.16, 11 P McKinney (Irl) 31.51, 12 M Gamonal (Spain) 32.03, 13 C McKhee (Irl) 32.05, 14 M Carroll (Sco) 32.12, 15 P Cassidy (Irl) 32.24.

Women: 1 C McKiernan (Irl) 33.39, 2 E Sadeeva (Ukr) 33.50, 3 A Rosa (Por) 34.02, 4 S O'Sullivan (Irl) 34.16, 5 J Bryne (Irl) 34.48, 6 P Curley (Irl) 35.04, 7 J Clague (Eng) 35.15, 8 J Augusto (Por) 35.41, 9 M Fernandez De Castro (Spa) 36.01, 10 T Maria Ramos (Spa) 36.19.

Team Race: 1 Ukraine 1hr 34min 53sec, 2 Portugal 1.35.19, 3 Ireland 1.37.35, 4 Spain 1.38.31, 5 Scotland 1.39.15, 6 Australia 1.39.39