Updated

Simon Thornton used a hole-in-one at the par-3 11th on Saturday to grab a share of the lead through three rounds of the Najeti Hotels et Golfs Open.

Spurred forward by the ace, Thornton fired a 6-under 65 and finished 54 holes at windy Aa Saint Omer Golf Club at 4-under 209. He is joined there by overnight co-leader Tjaart van der Walt (71) and local favorite Baptiste Chapellan (69).

For the second straight day Van der Walt couldn't maintain a 3-stroke lead coming down the stretch. On Friday, he tripped to three bogeys over his final seven holes. A day later, he suffered a double bogey at the 16th and a bogey at the 17th to drop into a tie with Thornton and Chapellan.

Seve Benson sits alone in fourth place at 3-under after a third-round 70, while Victor Riu (72), Chris Lloyd (70) and Max Glauert (69) share fifth at minus-2.

Overnight co-leader Robert Dinwiddie tripped to a 74 and dropped into a tie for eighth at 1-under. He stands alongside Jamie Elson (68) and Pelle Edberg (69).

Thornton came within a single stroke of equaling the course record of 64 on Saturday.

The 36-year-old was even through eight holes with a birdie and a bogey before he eagled the par-5 ninth to make the turn at even-par for the tournament.

Another eagle came in the form of a hole-in-one at the 11th, where Thornton found the cup with a seven iron from 206 yards.

"I was in between a seven iron and an eight iron and I hit a nice smooth seven and it was all over the flag, one big bounce and it just rolled in, it was really good shot," he said. "There were a few high fives and shouts, it was my first one in a professional tournament so I was delighted."

Thornton followed that apt effort with birdies at Nos. 12 and 15, then narrowly missed tying the course record when his 8-foot birdie putt at the last went just left of the hole.

"I was making greens and giving myself chances and I managed to take them today," he said. "The weather suits me, I like playing in a breeze. There were times when you could have hit any one of five clubs because the wind was unpredictable, but you just have to pick one and trust it."

Chapellan opened his third round with six straight pars before picking up birdies at Nos. 7 and 9. A run of five straight pars preceded a bogey on the 15th, but the 25-year-old rebounded with a birdie at the 17th to reach 4- under.

"I will do my best to keep my energy up in this weather and I have had a good strategy around this course so far this week so hopefully I can keep that going," he said.

Van der Walt got off to a steady start with six consecutive pars before closing his outward nine with an eagle at the par-5 seventh, a bogey at the next and a birdie at the ninth.

He added a gain at No. 12, opening a 3-stroke lead in the process, but once again the final stretch proved Van der Walt's undoing, as a double at 16 and a bogey on the next produced a 3-way tie at the top.

"My mistakes were so close to being good shots but in that wind anything can happen," Van der Walt said. "Overall I'm feeling comfortable and maybe tomorrow I can move clear of the field and then not drop back. I'm playing well so I just need to keep doing what I'm doing."

NOTES: All three leaders are seeking their first European Tour victory ... Thornton competes on the Challenge Tour ... Chapellan is playing in just his sixth European Tour event ... Dawie Van der Walt was the only 2013 winner in the field, but he could not recover from a 6-over 77 in his first round and missed Friday's cut ... The winner of this event receives a 1-year exemption to the European Tour. Co-sanctioned by the European Tour and the Challenge Tour, this is the only dual-ranking tournament of the 2013 season on the European Tour.