American Peter Uihlein holds a three-shot lead over the French duo of Gregory Bourdy and Thomas Levet at Celtic Manor.
The 24-year-old - who celebrated his birthday on Thursday - is chasing his second victory of the season at the ISPS Handa Wales Open.
He bogeyed the first but hit back with birdies at the next two holes before dropping another shot on the fifth.
He then holed from 10ft for an eagle on the par-five ninth and from much longer range for a birdie on the 10th to move to six under. He picked up another shot on the 14th before trading a bogey and a birdie at 17 and 18, repsectively, for a 67.
Levet was also four under for his round, while Bourdy shot a 70. The pair are one ahead of Sweden’s Peter Hedblom (66), Spain’s Rafael Cabrera-Bello (71) and Dutchman Joost Luiten (69)
Ireland’s Damien McGrane was on course to finish tied second with the French pair, but two late bogeys, on 16 and 18, cost him after three birdies on the back nine had moved him to four under. His 70, however, still left him in contention on two under.
David Higgins remained two over with a 71, while Gareth Maybin dropped back to six over with a 73.
Ryder Cup captain Paul McGinley, going so well before today, dropped back to three over with a six-over-par 77.
Hedblom, who has earned just €35,000 on the European Tour this season, moved into contention for the €348,660 first prize with his 66.
He made the halfway cut with two shots to spare after consecutive rounds of 72 left him two over par, but that was only seven shots off the lead as the players found scoring difficult at the former Ryder Cup venue.
His impressive third round was marred only by a bogey on the 16th and three-putt par on the 18th, and saw Hedblom set the clubhouse target early on.
The 43-year-old played just six times in 2011 before undergoing a shoulder operation in April and lost his card in 2012 after finishing 143rd on the Race to Dubai.
“It’s been tough and maybe I came back too early,” Hedblom said. “You think you won’t mind missing a few cuts because you want to play, but it gets into your confidence and I never really had one good round to get some confidence back.
“I’d play six, nine or 12 holes well and then make three or four bogeys and finish one under. Today I had two three-putts in the last few holes and shot five under so it could have been even better. I’m not sure what the leaders will do but I don’t think I will be more than five or six behind. I have not been very close the last couple of years so it’s going to be a fun day tomorrow.”