Henrik Stenson marked his return to the BMW PGA Championship with a strong opening round, but he was outshone by fellow Swede Johan Carlsson on a low-scoring first day at Wentworth.
Stenson, who is making his first appearance in the event since 2014, produced a strong finish to his four-under 68 over the newly-renovated West Course, while Carlsson ended the day in the outright lead despite a bogey at the final hole.
Scott Jamieson had set the early clubhouse target as he carded a 67 in the first group out, and he was joined in a share of second by Francesco Molinari and Kiradech Aphibarnrat, while Stenson's score was matched by Ryder Cup team-mate Thomas Pieters and another Swede in Alex Noren.
Carlsson, who is languishing at 136th in the Race to Dubai, made five birdies in seven holes in a classy outward 31 and, after dropping his first shot of the day at the 10th, he bounced back with back-to-back birdies at 11 and 12.
Another gain at the tough 15th took him two clear of the field, but he faltered coming down the last although the closing six did not affect his place at the top of the leaderboard.
Stenson was struggling to make much happen on the brand new greens as he parred the first 10 holes, but he also birdied 11 and 12 and picked up another shot at the 15th before a solid four at the long last completed an encouraging day for the world No 5.
Pieters had a great chance to join Carlsson in a share of the lead when he made three birdies in four holes from the 11th to get to five under, but the young Belgian found the hazard with his second to the 18th and signed off with a disappointing six.
Wentworth member Ross Fisher and Ireland's Shane Lowry were among the group on four under along with Branden Grace, who insisted his "conscience was clear" after being awarded a questionable free drop from a plugged lie in a bunker at the 13th.
Tyrrell Hatton, who was one off the lead heading into the final round at Wentworth last year, made a positive start with a 69 thanks to three birdies in five holes from the 12th, while veteran Lee Westwood is a further shot back after failing to build on a fast start as he followed a birdie at the second with an eagle at the fourth.
Defending champion Chris Wood was disappointed to miss a number of short-range putts in an opening 72, the same score as his opening round 12 months ago, while Olympic champion Justin Rose and out-of-sorts Danny Willett are also level par.