Frankie Dettori, who swiftly had to revert to bare-back riding when his saddle slipped on Ski Run at York last month, will be hoping for a more conventional ride when he resumes his association with Gerard Butler's useful filly at Doncaster tomorrow.

Ski Run goes for the £40,000 Rothmans Royals Park Hill Stakes and has every chance of emerging triumphant in this Group 3 contest.

Lightly-raced this season, Ski Run won a handicap at Ascot on her second start and was then thrown into the deep end in the Group 3 Lonsdale Stakes on Knavesmire.

As it turned out, she was challenging for the lead approaching the final furlong when her saddle suddenly slipped backwards.

Dettori, very much alive to the situation, kicked his feet out of the stirrups and perched on his mount's bare back until after the winning post.

That Ski Run still managed to finish third to Royal Rebel in that useful contest, beaten just over three lengths, speaks volumes for her performance. Just how close she would have come had Dettori been able to ride her all the way to the line, is anyone's guess.

Tomorrow, Ski Run will surely be fitted with a breast-girth, designed to prevent a saddle shifting backwards, so there should be no repeat of the York episode. A bold bid for victory is anticipated.

The £200,000 St Leger Yearling Stakes is the richest race on the card, a two-year-old event confined to those horses which were bought at the sales - across the road from the racecourse - 12 months ago.

With a maximum 22 runners, the field is very much a mixed one, but Pan Jammer stands out as a horse with a touch of class.

Mick Channon's youngster, twice a winner this season, finished a very creditable fourth after a slow start in the Richmond Stakes at Goodwood last time. Provided he gets away on terms here, he should be involved in the finish.

The £30,000 Tote Trifecta Portland Showcase Handicap over five-and-a-half furlongs is a typical wide-open sprint.

Settrington trainer John Quinn has strong claims with the in-form Smart Predator.

A horse who has progressed and matured with every passing month this season, Smart Predator trotted-up at Yarmouth on his latest start, having previously been narrowly beaten at Goodwood - with an easily forgotten effort at Beverley, where he had no chance at the draw, sandwiched in between.

Tomorrow's distance and ground should be ideal for Smart Predator, who has been raised 7lb for his Yarmouth victory. He is napped to keep pace with the handicapper.

The potentially high-class Tempest (1.30) is another to note on the first leg of Doncaster's four-day St Leger meeting, while Forever Times (2.05), badly drawn at Beverley last time, should be given another chance.

At Epsom, look out for the in-form sprinter Rita's Rock Ape (2.55) and Riberac (4.30), the latter being trained by Mark Johnston, who yesterday at Hamilton achieved the victory he needed to give him the fastest 1,000 winners in Britain.