Trent and Cortaflex Levitation NZPH headed home a 19-strong field that saw eight through to the jump-off over the Gerrit Beker designed course.
In winning, Trent picked up GO and RB Hansen Memorial Trophy and the Hikurangi Memorial Cup. The Hansen trophy is in memory of brothers Graeme and Bruce Hansen, who both rode at the Olympics.
Trent, from Hawkes Bay, had the luxury of being the last to go in the jump-off which saw no-one sitting on zero faults - both clear rounders and four faulters had been carried through to the second round, with faults accumulating.
So Trent went in knowing all she had to do was leave everything up in a reasonable time.
"It was nice to have a double clear and win rather than a speed demon jump-off," she said.
And she was chuffed for Levi too, after so much attention on her US-based world cup horse Cortaflex Muskateer NZPH.
"Everyone had forgotten a bit about Levi, so it's nice he has come back so well." Levi had a windpipe operation in April and has come back better than ever.
"I knew he would, but with horses, there is always that little shadow hanging over you," said Trent. "He's so happy to be back competing."
The grand prix is one of the few classes Trent has not won at Gisborne before.
A few others picked up unlucky rails, including Catherine Cameron (Cambridge) and Kahurangi Tardak who were going sweetly until the wind blew down a nearby fence startling both her and the horse, and leaving them eight faults worse off.
Simon Wilson and Right Royal carried four faults through from the first round but jumped a beautiful clear in the second, and fast enough to secure second slot.
Many of those who started at Gisborne will head to Hawke's Bay for the opening round of the world cup later in the week.
In the pony grand prix the in-form Luke Dee (Gisborne) and Wild Thing were the victors in a toughly fought jump-off.
Even Dee was surprised to have won the class with Wild Thing, the only one of his trio he had in the jump-off.
He was second to last to go, with Amanda Wilson (Northland) on Showtym Gladiator on his heels. If there's a combination to show no fear at matching a time, it's this one. Dee had a rail at the Kelso wall but clocked at 35.47.
"When Amanda went clear at the wall I thought she had it," he said.
But they dropped the last after a tight turn and ended up in fourth place.
Dee should have had a little faith, though - he won every class he entered at the show.
Gisborne herald Cathay Pacific horse grand prix: Anna Trent (HB) Cortaflex Levitation NZPH 1, Simon Wilson (Waipukurau) Right Royal 2, Katie McVean (Mystery Creek) Dunstan Daffodil 3, Catherine Cameron (Cambridge) Kahurangi Valentino 4, Maurice Beatson (Dannevirke) My Gollywog 5, Catherine Cameron (Cambridge) Kahurangi Tardak 6.
Kiwispan junior rider: Taylor Mason (Wellington) Just Joop 1, Jake Lambert (Matamata) Miss Anonymous 2, Donna McKinley (Whakatane) Relish 3, Lisa Hogg (Ohope) Jumping Jack Flash 4, Summer Hardie Hurles (Whakatane) Dawn to Dusk 5, Gemma Booth (Wairoa) Ipod 6.
Open horse 1.3m classic: Maurice Beatson (Dannevirke) Kiwi Relic 1, Claire Wilson (Waipukurau) Tipsey 2, Ike Unsworth (Tauranga) Whitaker MVNZ 3, Ike Unsworth (Tauranga) Wimbledon MVNZ 4.
Mitavite six year old: Lisa Coupe (Kumeu) Bates Amaretto MVNZ, Lisa Coupe (Kumeu) Bates Limerick GNZ, Anna Trent (Hawke's Bay) Cortaflex Quickstep NZPH, Katie McVean (Mystery Creek) Dunstan Zasjany D, Sarah Aitken (Gisborne) Istacruiz, Karen Riddle (Cambridge) The Mighty Quinn =1.
Astek five year old: Anna Trent (HB) Cortaflex Romco NZPH, Harvey Nelson (HB) Darkages, Katie McVean (Mystery Creek) Dunstan Springfield, Karen Riddle (Cambridge) Littoria WS =1.
FMG pony grand prix: Luke Dee (Gisborne) Wild Thing 1, Jake Lambert (Matamata) Co Calico 2, Amanda Wilson (Northland) Showtym Viking 3, Amanda Wilson (Northland) Showtym Gladiator 4, Madison Rawson (Gisborne) Kabo Silver 5, Tinesha Carey (HB) Hi Hat 6.
Open pony classic 1.1m: Freya Gordon (HB) Dixie Chic 1, Freya Gordon (HB) Millbank Idaho 2, Rebecca Porter (HB) Mr Bee Brown 3, Molly Coutts (Northland) Showtym Boy 3, Meg Lambert (Matamata) Silver and Gold 4.