NORTH Yorkshire's Nicola Tweddle was in great form at the Windsor International Horse Trials, where she made the top 20 in a quality field which included several Olympic medallists.

The two star three-day event ran over the Queen's glorious parkland surrounding Windsor Castle and was won by Rolex Grand Slam and Badminton winner Pippa Funnell on the ex-racehorse Blue Horizon.

Tweddle rode the eight-year-old bay mare Don't Underestimate for owner Tracy Darby. The horse made a reasonable start in the opening dressage phase to stand 30th of the 100 plus starters, 15 marks off the lead.

She then jumped a superb clear inside the optimum time over the testing 26-fence cross-country course, which included some narrow combinations and a four-part water complex, to move into tenth spot.

Concerns about the going led to several riders pulling out before the cross-country, including 2005 Badminton runner-up William Fox Pitt on both his rides, although it appeared to ride well.

"I felt my horse did a nice dressage test and gave me a good ride cross-country," said Tweddle. "We took some long routes as I was up on time and wanted to make sure of getting home safely. The cross-country course was very nice, but had lots of skinny, difficult fences which Don't Underestimate coped beautifully with. The ground was firm, but the organisers had tried hard."

A place in the top eight looked possible coming into the final day's show jumping phase, but two fences fell on the twisty course to push the pair back to a still highly creditable 16th spot.

"The show jumping course was quite influential, with some testing related distances and quite a tight time, and it's never been this horse's best phase," Tweddle added.

"I was delighted with her overall, especially as she is still young for this level of competition - it was a very enjoyable event."

Tweddle will be at the Hexham one-day event this weekend, when she will ride several up and coming horses in what is proving a busy and successful season for the highly talented 28-year-old.