Daniel Gavins carded a bogey free 65 to come from seven shots back and win his first European Tour title at the 2021 ISPS HANDA World Invitational presented by Modest! Golf Management.
The Englishman arrived at Galgorm Castle Golf Club off the back of two top tens on the European Challenge Tour but had never recorded one on the European Tour and looked an unlikely winner coming into day four at eight under.
But as leading challengers Jordan Smith and David Horsey moved in the wrong direction, Gavins holed two putts of over 50 feet on the back nine to get to 13 under and win by one shot from Horsey, who carded a closing 72.
In the women's event, Thailand's Pajaree Anannarukarn took the title with a victory over American Emma Talley on the second play-off hole after the duo had finished at 16 under.
A Qualifying School graduate in 2016 and 2018, Gavins' best finish to date on the Race to Dubai Rankings in Partnership with Rolex was 178th in 2019 but he will move comfortably inside the top 100 with this win and will no longer have to worry about his playing privileges.
He entered the season without a top ten on either the Challenge or European Tour but has five on the 2021 Road to Mallorca and is now a European Tour winner in his 53rd appearance after bringing that form to Ballymena.
"I was a little nervous before but I just tried to shoot as low as I could today," said Gavins, who played on the EuroPro Tour in 2017 and 2018. "At seven behind I didn't really think I was within a chance of winning so there was maybe a bit less pressure there.
"I've been playing well but I was going to have the week off because I knew there's a lot of Challenge Tour events coming up so I thought a week off here maybe and then play the rest of the Challenge Tour.
"I just can't believe it, it'll take a while to sink in, an amazing day.
"It's amazing that every week on the European Tour is just a place you want to be. I'm just fortunate to be on it and just playing golf."
It's amazing that every week on the European Tour is just a place you want to be. I'm just fortunate to be on it and just playing golf
Horsey started the day a shot off the lead but holed from five feet on the fourth and 18 on the next to get into a share.
He dropped a shot on the sixth after leaving his ball in a bunker but had a two shot lead, with overnight leader Smith finding the trees, failing to get out and then three putting from the fringe for a triple bogey.
An approach to ten feet at the eighth meant Horsey kept his two shot cushion at the turn but it was all to change on the back nine.
Hillier had put a pitch to two feet at the first but gave the shot back on the fourth after finding the water before putting a tee shot to 12 feet at the seventh. A two putt birdie on the tenth looked to keep him in contention but he was soon in a tie for the lead.
Horsey found the water at the 11th and kept the damage to one shot but he could not repeat the trick when he found the hazard again on the 13th, failing to get up and down and slipping to 13 under.
That put him not only alongside Hillier but also Gavins, who holed three huge putts to set the target.
The 30-year-old drove the green at the second, holed a bunker shot at the fifth and then made a 60 footer from the fringe at the sixth to turn in 31.
More magic with the short stick was to come as a pair of 50 footers on the 13th and 16th then left him with an anxious wait, with the final group still in the thick of it.
Hillier dropped out of the lead after a poor tee shot on the 16th and a three putt on the next meant a birdie on the last would secure the title for Horsey.
But the Englishman sent his tee shot a long way left, losing his ball and dropping a shot to hand Gavins the trophy.
Englishman Smith carded a closing 74 and Kiwi playing partner Hillier got round in 70, with Kawamura securing a second consecutive top five with a 69, two shots more than Cañizares.
It was a dramatic final day for the women's event as Jennifer Kupcho held the solo lead over Anannarukarn and Talley stood on the 16th tee.
But the American would bogey the 16th and 18th and miss out on the play-off as her playing partners both made birdie on the penultimate hole.
The first trip back up the last would be halved in pars but a Talley bogey on the last meant Anannarukarn was left celebrating.
"I just wanted to keep doing what I've been doing and really try to stay focused on my game and obviously it turned out good," she said. "I'm really thankful for everything, everything that I've been through."