The 32-year-old Irish athlete stormed home in 51 minutes exactly, beating the mark set by Colleen DeReuck in Washington four years ago by 16 seconds.

O'Sullivan, the European 5,000 and 10,000m silver medallist in Munich last month, showed she meant business from the start.

She went through the first mile in four minutes 57 seconds and maintained record pace to finish well clear of Australians Susie Power and Natalie Harvey.

Although O'Sullivan is remaining tight-lipped about her future plans, her road race schedule would suggest she is gearing up to run a marathon in the autumn.

The New York Marathon on 3 November, where she has close ties with the organising committee, is looking the likeliest location.

When asked about her marathon prospects O'Sullivan said: "Of course the win and the time has told me a lot."

O'Sullivan is in a rich vein of form at the moment, having missed the 5km world record by just two seconds in London last week.

She will return to action later this month when she lines up alongside Paula Radcliffe in the Nike London 10k Run.

However, O'Sullivan does not plan to race against Radcliffe, instead using the run as a training exercise.

She will then compete in the BUPA Great North Run on 6 October and the Great Ireland Run a week later.

"I've now got a fast 10 miles time and I'll be aiming to run under 70 minutes for a half marathon in the Great North Run," said O'Sullivan.

"That will tell me a lot more about my shape."

She said of her record breaking performance: "I knew I was heading for a time of under 52 minutes, but still didn't think De Reuck's record was on.

"However, returning to the seafront, there wasn't a breath of wind and I decided to give it everything I had.

"Coming down the finishing stretch was a great feeling, the spectators were making me try harder and harder."

In the men's event, Simon Kisamili won his second Great South Run title in four years ahead of English pair Matt O'Dowd and Ben Noad.

The Kenyan outsprinted O'Dowd to take the title by two seconds in 47:27.