Rory McIlroy endured an opening round to forget at the BMW PGA Championship as Matt Wallace set the early pace at Wentworth.
Englishman Wallace carded a blemish-free 65 to sit on seven under par at the top of a star-studded leaderboard, one clear of Henrik Stenson and Jon Rahm.
Justin Rose sits alone on five under, while Ernie Els and Paul Casey are among a nine-man group a further shot back after Thursday's play.
McIlroy, however, faces an uphill battle just to make the cut after a promising start unravelled in spectacular fashion, forcing him to sign for a score of 76.
He was three under through five holes, but his day began to go awry around the turn with three successive bogeys from the eighth onwards.
A birdie at the 12th suggested it was merely a temporary blip, only for this year's FedEx Cup winner to endure a nightmare finish. There were three bogeys and a double in his closing six holes, with a frustrated McIlroy then declining to speak to the media after his four-over round.
Wallace, who lives nearby and plays the course on a regular basis, was understandably happy to discuss his performance after shooting five birdies and an eagle.
"I've played the course plenty of times before coming into this week and feel comfortable and it always helps when your game's in shape as well," he told the European Tour website.
"I just want to play better and I want to keep getting better and put myself in positions to win tournaments. It's a good start. We've got a long way to go, though."
Rahm produced an impressive finish to charge towards the summit, the Spaniard posting four birdies in his final five holes. As for Swede Stenson, he joined his 2018 Ryder Cup team-mate on six under courtesy of a successful yet somewhat bizarre eagle putt from off the green at the 18th. Stenson's ball bobbled up as soon as it was struck but nevertheless found its target from distance.
Rose bloomed late too, a birdie at his final hole taking him to five under. The Englishman has twice finished second at the tournament, including losing in a play-off to Anders Hansen in 2007.
Meanwhile, defending champion Francesco Molinari started his title defence with an opening 69, leaving him in a logjam at three under.