In the preceding 13 miles, on the rain-lashed, windswept road from Newcastle, track and field's golden girl of 1998 had no need to take off the metaphorical gloves. The bat in the women's section of the Tyneside half-marathon - which attracted 40,000 entrants - proved to be a non-contest.
O'Sullivan won in a canter, an elegant one at that. The seemingly effortless manner in which she eased clear in the final three miles made a mockery of both the conditions and the opposition.
It could have been a Sunday training run for the Irishwoman who, at 28, has revived her flagging career this year. Instead, in her first serious half-marathon, she left the European marathon champion trailing helplessly in her wake.
Manuela Machado, the 1995 world marathon champion, was a beaten woman by the 10-mile mark. The Portuguese runner trailed in one minute and five seconds after O'Sullivan had passed under the finishing banner, which happened to bear the legend "You're amazing".
Few athletes anywhere on the globe have been as amazing in 1998 as the woman from Cobh. Winner of the short and long-course races at the world cross-country championships in Marrakesh in March and of the 5,000m and 10,000m finals at the European Championships in Budapest in August, she rivals Marion Jones as track and field's leading lady of 1998.
She puts her feet up as the first Irish winner in the Great North Run since John Treacy beat Steve Jones in 1988. Lasse Viren also ran that year and the Finn who twice achieved the Olympic 5,000m and 10,000m double was only two minutes quicker, in perfect summer conditions, than the women's 5,000m and 10,000m champion of Europe was in sub-zero temperatures yesterday.
O'Sullivan's time, 71 minutes and 50 seconds, was not slow. But it was clear from her relaxed demeanour from the start that she could have run faster. "For most of the way I didn't feel I was working hard," she confessed. "But today was not the day for fast times. The most important thing was winning."
It was another important win, too, for an Irishwoman on English roads, following Catherina McKiernan's victory in the London Marathon in April.
The pair could meet on Irish soil in March, when the world cross-country championships are contested in Belfast. That challenge is the next target for O'Sullivan but the winner of the men's race yesterday, Josia Thugwane, will be aiming to be crowned marathon king of New York on 1 November.
With his 5ft 2in frame and his anomalous sunglasses, the South African cut a contrasting figure to the 5ft 9in O'Sullivan. The Olympic marathon champion was just as commanding, though, crossing the line in 62min 32sec - 18 seconds ahead of John Mutai, a Kenyan based in Coventry.Reuse content