Pre-race favourite Back In Focus won the John Oaksey National Hunt Chase to open Ladies' day in a thrilling finish.
The horse, won the longest race of the Festival in the closing run to the line, overhauling Tofino Bay.
Willie Mullins has now trained four winners out of seven races run at the Festival.
His son, Patrick Mullins, was riding Back In Focus
The New One, ridden by Sam Twiston-Davies,won the Nepture Novices' Hurdle, an extended two-mile race.
Pont Alexandre and Ubak led the whole way, but it was The New One, backed by our racing editor Jonathan Herbert, who snatched victory from pre-race favourite Pont Alexandre.
Despite Pont Alexandre stretching ahead to a length lead with one to jump, urged on by Ruby Walsh, The New One, trained by Sam's dad Nigel, romped home to win comfortably.
Pont Alexandre evenutally finished third.
Lord Windermere won the RSA Chase with jockey Davy Russell after Boston Bob, already fading at the final hurdle, fell.
Lord Windermere broke clean and saw off Lyreen Legend to cross the line first.
Pre-race favourite Unioniste could not make up ground and jockey Ruby Walsh could not do much to change the standings. The horse finished fourth.
Sprinter Sacre more than lived up to expectations in the two mile feature race of the day, the Queen Mother Champion Chase. The odds-on favourite streaked ahead of Sizing Europe with two jumps to go to secure a thoroughly convincing victory.
Second was Sizing Europe and third was Wishful Thinking.
Medinas, one of the smallest horses in the 28-strong field, had a surging finish to sneak home to win the Coral Cup ahead of Meister Eckart and Fiveforthree in a close finish.
Wayne Hutchinson was the jockey.
Pre-race favourite Prendra, backed by Herbert, could not make up any ground.
The Fred Winter Juvenile Handicup Hurdle was won by Flaxen Flare, second was Caid De Berlais and third was Ptit Zig, fourth was Milord and fifth was Totalize.
Briar Hill, trained by Willie Mullins and ridden by Ruby Walsh, won the last race of the day, the Weatherbys Champion Bumper.
