|BMW PGA Championship second-round leaderboard|
|-12 K Aphibarnrat (Tha) -11 L Canter (Eng) -10 A Scott (Aus), F Laporta (Ita) -9 B Horschel (US), J Rose (Eng), J Donaldson (Wal)|
|Selected others: -5 T Fleetwood (Eng) -4 L Westwood (Eng) -3 M Fitzpatrick (Eng) -1 T Hatton (Eng), I Poulter (Eng)|
Englishman Laurie Canter shot 66 to move one shot behind BMW PGA Championship leader Kiradech Aphibarnrat after the second round.
Canter, 31, carded eight birdies and two bogeys at Wentworth, where Ryder Cup spots are up for grabs.
He finished on 11 under, three shots ahead of former Open champion Shane Lowry, who is seeking to automatically qualify for Europe's team.
"Given my recent form, it's just nice to be playing tomorrow," Canter said.
"If I knew what was different from the last few weeks I would tell you, but I don't. It's golf. I don't think there's much of a difference between playing well and not."
Thailand's Aphibarnrat added a 68 to his opening 64 on the West course to post a halfway total of 12 under .
He leads by one from Canter, with former Masters champion Adam Scott on 10 under and English Ryder Cup hopeful Justin Rose another stroke back alongside Welshman Jamie Donaldson.
Europe will seek to defend the Ryder Cup against the United States at Whistling Straits in Wisconsin from 24 to 26 September.
Paul Casey, Tommy Fleetwood, Viktor Hovland, Rory McIlroy and Jon Rahm have already booked five of the nine automatic places.
The four remaining qualifiers will be decided this week, with European captain Padraig Harrington then naming three wildcards after the tournament at Wentworth ends on Sunday.
But Ryder Cup veteran Lee Westwood has questioned the qualifying system.
Westwood and Lowry's places are under serious threat from Austria's Bernd Wiesberger, who would overtake McIlroy in the European points list with a top-50 finish or better.
That would mean McIlroy qualified via the world points list instead of Lowry, who in turn could knock Westwood out with a top-eight finish or better, depending on the Englishman's finish in Surrey.
Whoever missed out would join the likes of Ian Poulter - who missed the halfway cut - Sergio Garcia and Rose in vying for one of Harrington's wildcards, although the former US Open champion can still qualify automatically with a win.
Wiesberger was three over par after six holes of his first round, but finished birdie-eagle and added a superb 67 to end the day inside the top 20 on six under, two shots behind Lowry.
Westwood made four birdies on the back nine to sign for a second successive 70.
"I'm here to try and win the BMW PGA Championship and Sunday night, if you're in the team, then you start thinking about the Ryder Cup," Westwood said.
"There's so many variables as well with the way we've set up the qualification this time around. This tournament is heavily loaded compared to everything else we've done and I think it's something to maybe look at in the future."
Canter shone despite getting up at 4am to watch Emma Raducanu's US Open semi-final tennis win in New York.
"I had a 4.30 alarm anyway so thought 'why not set it a bit earlier'," said Canter, who was a promising tennis player himself before opting to focus on golf.
"She looks like she has the world at her feet and hopefully we will be watching her for years to come."
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