Kevin Gallagher won the €12,000 (£10,853) Premier Grand Prix as Horsesport Ireland's Premier series concluded at Portmore, Aghalee.
The clever track produced great excitement as riders faulted galore, but Gallagher - with Greg Broderick's Ballypatrick Flamenco - overhauled leader Kenneth Graham's, on Willie Lapsley's Touchdown gelding George, time of 47.48 to win in 46.98. Both riders produced the only double clears from 34 starters.
"My horse tried his heart out," said Gallagher. "It was a tough and challenging course but he was fantastic. I am delighted."
It was also a successful day for Captain Geoff Curran, who lifted the National 2020 Showjumping title.
Belfast's Joanne Blair excelled to take the five-year-old title on David Prentice's My Clementine from 32 starters, having earlier won the 1m30 on Samantha Dale's Roundthorn Hercules.
Graham was on the podium again after steering Kilmac VDL, owned by Aiden McGroy, to runner-up in 38.01.
Fermanagh's Catherine Thornton took the six-year-old honours aboard Coachella, owned by lough shore farmer David Campbell, with the fastest clear in 36.71 ahead of Graham and Regula Wassmer's Tullabeg Jackson in 38.22.
The Ulster Region Grand Prix Horse Show moves to the Meadows, Lurgan this coming Saturday.