FLAT turf racing gets under way at Doncaster today with both Pat Eddery and Frankie Dettori in action.

But the two jockeys expected to dominate this season's championship can be upstaged by Ray Cochrane in the feature Sporting Life Doncaster Mile.

Cochrane, who recently returned from injury, partners Yeast for William Haggas in this listed contest.

Yeast enjoyed an excellent 1996 with wins in the Victoria and Royal Hunt Cups and a listed race at Newmarket in October to his credit. But arguably the son of Salse's best performance came in an Ascot handicap in July.

Under the steadier of 10st, Haggas's gelding employed his usual front running tactics and galloped his rivals into the ground to come home an impressive three length winner from Master Charter.

Yeast, who has reportedly been working well at home with Worthington Lincoln Handicap favourite Alamein, can give the latter's prospects a boost with victory today.

River's Source can shake off his maiden tag at the third attempt in the Mellon Wood Maiden. Barry Hills's three year old ran promisingly on both starts as a juvenile, finishing fourth of 18 to Dacoit, beaten around four lengths, in a Salisbury maiden and a twolength runner up to Attitude at Leicester.

In the latter race the Irish River colt still carried plenty of condition but held every chance two furlongs out only to be outpaced inside the distance.

Open to considerable improvement, River's Source looks set to get his season off to a good start.

Sword Arm merits consideration in the Back A Winner By Train Handicap over an extended 10 furlongs.

Roger Charlton's three year old has already shown himself in good order this year with an easy one length victory on Wolverhampton's fibres and, leading on the bit over one furlong out and coming home hard held from Little Acorn.

The type to progress, Sword Arm is taken to register his first win in a handicap.

Pat Eddery was given a snub yesterday, 24 hours before he begins the defence of his British Flat jockeys' championship on turf. He is offered at 16 to 1 to gain the 12th title of his career by Paddy Power, who quote no fewer than four of his rivals at shorter prices.

Frankie Dettori, put out of contention last year by injury and suspension, is 4 to 9 favourite.