Ludvig Aberg takes a two-shot lead into the final round at Wentworth
Playing in only his 10th event since turning professional in June, Aberg carded an eagle and five birdies against a lone bogey to close on a 16-under par total of 200.
Tommy Fleetwood of England, Aberg's Ryder Cup team-mate, shot 67 to share second place on 14-under with Scotland's Connor Syme (65), who surged into the mix with a superb back nine of four birdies and an eagle.
Aberg won the European Masters in Crans-Montana two weeks ago, earning a call-up to Europe's team for the Ryder Cup later this month. He said winning the BMW PGA Championship was "very, very high" on his list of goals.
"It is one of the biggest events on the DP World Tour," said Aberg, a former top-ranked amateur player who excelled on the US college scene. "I've got memories of Alex (Noren) winning here when he hit an unbelievable shot into 18.
"It's really cool to see myself up there, I have to pinch myself in the arm every now and then but it's quite cool. I think expectations just changed after Switzerland in terms of knowing I can do it.
"Even though I've won in college quite a bit it is different ... to win on the pro stage and it was pretty cool to do that. I could tell myself that I could do it and was good enough, and hopefully I'll be able to do that tomorrow, too."
Callum Shinkwin shot a bogey-free 64 and was at 13-under along with fellow Englishman Aaron Rai (67) and New Zealand's Ryan Fox (66).
Masters champion Jon Rahm (66) was a further shot back after closing with two birdies while world number two Rory McIlroy (67) was 10 shots off the pace as all 12 players from Europe's Ryder Cup team made the cut for Sunday's final round.
