Rory McIlroy's bid to equal his career-best season got off to a nightmare start in the opening round of the BMW PGA Championship.

McIlroy has won the Players Championship, Canadian Open and Tour Championship in 2019 but was determined not to rest on his laurels as he tries to close the gap on world number one Brooks Koepka.

The 30-year-old felt he was more than capable of winning two of his last five events to match the five wins he achieved in 2012, but slumped to a four-over-par 76 in glorious conditions at Wentworth.

The world number two got off to an ideal start with an eagle from 12 feet on the par-five fourth and a birdie from even closer range on the next.

However, McIlroy then dropped three shots in a row from the eighth and had to hole from 10 feet to save par on the 11th after his approach flew over the green.

A two-putt birdie on the par-five 12th got McIlroy back into red figures but he promptly bogeyed the 13th and was fortunate to drop just one shot on the 15th after his drive finished just yards from going out of bounds.

There was no such reprieve following a pulled drive on the 17th which led to a double-bogey seven and McIlroy's misery was completed with a bogey on the last, after which he declined to talk to waiting reporters.

At the top of the leaderboard, England's Matt Wallace had set the clubhouse target on seven under par thanks to an eagle and five birdies in a flawless 65.

"I played the first seven or eight holes as good as I possibly could and showed my all-round game by grinding out the last few holes," Wallace said.

"I'm very happy. Whenever you can get off to a start like that it builds your confidence and just follows on from last week in Holland."

Wallace enjoyed a one-shot lead over Sweden's Henrik Stenson, whose 66 equalled his lowest round at Wentworth and was completed in style with an eagle on the 18th.