Matt Wallace believes his decision to part company with caddie Dave McNeilly is paying dividends after claiming the lead in the BMW PGA Championship at Wentworth.Wallace carded an eagle and five birdies in a flawless opening 65 to enjoy a one-shot lead over former Open champion Henrik Stenson and Spain’s Jon Rahm, with Justin Rose a shot further back.Danny Willett and Paul Casey were part of a seven-strong group on four under par, but pre-tournament favourite Rory McIlroy slumped to a four-over-par 76 after playing the back nine in 42 shots.From extras.Wallace was heavily criticised on social media for berating McNeilly towards the end of June’s BMW International Open, where the defending champion twice found water on the 72nd hole as he chased a birdie to force a play-off.The 29-year-old Londoner initially cleared the air with McNeilly and they worked together at the Open at Royal Portrush – where Wallace played alongside Tiger Woods for the first two days – but the split came four days after the World Golf Championship event in Memphis.“It was the hardest decision I’ve had to make in my career,” Wallace said. “He’s done so much for me. He’s got me to where I am today but it was a time and a decision that I wanted to be done and change something up.