BRITISH star Oliver Townend has put himself in strong contention to win eventing's richest prize - the £255,000 Rolex Grand Slam.

Townend leads the Mitsubishi Motors Badminton Horse Trials after dressage on a score of 20.8 penalties - the best dressage performance at Badminton for 18 years - with Ballaghmor Class.

The Grand Slam is awarded to any rider who wins consecutive Burghley, Kentucky and Badminton crowns, but it has only been done twice before, by Britain's Pippa Funnell in 2003 and Germany's double Olympic champion Michael Jung two years ago.

Yorkshireman Townend already has Burghley and Kentucky in the bag, and he is now also chasing Badminton's £100,000 top prize.

When Kentucky prize money from last weekend is added, he could leave for home in Shropshire on Sunday with an eight-day £460,000 windfall.

"He is still a young horse, but he felt very much on side today the minute I sat on him," said new world number one Townend, of his 2017 Burghley champion Ballaghmor Class.

"I am seriously happy with him. He stepped up again from Burghley in what is only his second four-star event."

Townend leads from 62-year-old New Zealander Mark Todd - the oldest competitor in this year's field - with Kiltubrid Rhapsody, and first-day leader Ros Canter is third aboard Allstar B.

Attention now turns to Saturday's key cross-country phase, with soft going looking likely to favour the early starters.

Townend is a morning performer on his other ride Cooley SRS, in equal 15th place, but he will be the penultimate competitor to go with Ballaghmor Class.

"It is going to be a slog," he added. "The ground is going to be testing - a real stamina test - and it is a course where you could have an easy mistake."

Wiltshire-based eventing master Todd, a twice Olympic individual gold medallist, delivered a magical display in pursuit of a possible fifth Badminton title following victories in 1980, 1994, 1996 and 2011

"It is nice to know I am still improving!" a delighted Todd said.

"This is only the horse's second four-star, but he has got a brilliant temperament. Nothing really seems to bother him."

Fourth-placed Cooley Rorkes Drift, meanwhile, made a superb Badminton return with rider Jonty Evans nine months after Irish Olympian Evans launched a crowd-funding campaign and online auction to raise money to buy it.

The owner wanted to sell, but Evans' fund reached its £500,000 target just over a month later, enabling him to keep the ride after almost 7,000 people made donations.

William Fox-Pitt is also firmly in the title shake-up on his first appearance at Badminton since he won it with Chilli Morning three years ago.

The Dorset-based former world number one suffered a serious head injury while competing in France in October 2015 and he spent a week in an induced coma.

Although he returned to action for the Rio Olympics, this year's Badminton represents a four-star event comeback.

"It is quite emotional," said Fox-Pitt, who posted a dressage score of 27.1 on Fernhill Pimms to lie 19th overnight, but within sight of the leaders.

"I was on the wait-list to be here. Badminton was never on my radar at all, and I only knew last week that I was in. It has been a long time - Rio was a while ago."

The cross-country test sees competitors tackle 32 jumping challenges over a course more than four miles long and with an optimum completion time of just under 12 minutes.