Open champion Shane Lowry is tied for the clubhouse lead with Matthew Fitzpatrick after a superb 65 at the BMW PGA Championship at Wentworth.

Aided by an old putter he "whipped out of the cupboard" on Monday, Lowry carded an opening 67 to lie one shot off the lead shared by Tyrrell Hatton, Justin Harding and Adri Arnaus.

Among the early starters, the 33-year-old carried on where he left off on Friday with birdies on the 12th, 13th, 17th, 18th, fourth, fifth and seventh to move to 12 under.

"It's funny, I really only decided to come here on Sunday," Lowry told Sky Sports. "I wasn’t too sure whether I was going to play or not.

"I went to get my clubs and just seen this putter sitting there. I had a look at it and said I’ll bring it for the spin anyway and get a new grip on it.

"Then I went and played nine holes with my coach on Monday evening at the K Club and I putted quite nicely. So I brought it, put a new grip on it and decided to use it. It’s definitely worked so far."

Englishman Fitzpatrick was in sensational form up until the eighth hole, his last. He was on course for a nine-under 63 until he found the water with his second shot and wound up with a double-bogey six to match Lowry's 65 and join him at -12.

Fitzpatrick's card was littered with seven birdies and one eagle, on the par-five fourth, before that final hole.

Padraig Harrington also eagled the fourth hole and birdied the seventh to move onto three under par, but bogeys on two of his final three holes saw him finish the day on -1.

Offaly native Lowry bounced back from the disappointment of a missed cut at the Irish Open as he recorded no bogeys in a round that should leave him well in the mix going into the weekend.

Lowry is currently 40th in the Race to Dubai after spending most of the interrupted 2020 season playing in the United States.

"I feel like my game has been good for a while but I’ve been struggling on the green," said Lowry.

"It’s amazing when you hole a few putts. I’ve probably driven it a little bit better this week than I have done all year.

"I’ve been dropping a lot of silly shots on the golf course and it takes its toll, especially playing golf on the cut mark. I’ve not been missing a whole lot of cuts but just playing golf on the cut mark is stressful and hard.

"When you go out and shoot a good score in the first round and then get off to a good start in the second round like I did, it frees you up and allows you to go and play some good golf.

"Thankfully that’s what I’ve done and hopefully I can keep doing it this weekend."