Ireland's London 2012 individual bronze medallist Cian O'Connor captured the main evening class with victory in the Christmas Pudding Stakes in London.
Riding chestnut gelding Splendor, O'Connor comfortably won a seven-horse jump-off, beating Great Britain's Tina Fletcher and Hello Sailor by two and a half seconds.
"You take chances you wouldn't normally take at this show," O'Connor said.
"After the turn to the double I thought 'Did I really do that?' But this place, and the fantastic crowds, make you do that."
Fletcher, back in action following a serious ankle injury, was thrilled with Hello Sailor's performance, a horse she is aiming at next year's European Championships in Denmark.
"I am chuffed to bits, it has been a long time out of the ring for me," she said.
O'Connor is Ireland's only representative at the Olympia venue, where the World Cup Qualifier takes place on Saturday afternoon and the Grand Prix on Sunday night.
Meanwhile, Antrim-born Jessica Kurten flies the Irish flag at Madrid's three-star competition in Spain, where she will compete with three horses this weekend.