WGC Bridgestone Invitational: Thomas Pieters takes first-round lead
|Bridgestone Invitational first round|
|-5: T Pieters (Bel) -4: R Knox (Sco) -3: R McIlroy (NI), B Watson, J Spieth, K Kisner, (US), R Fisher (Eng), J Rahm (Spa) Selected others: -2 D Johnson, C Hoffman (US); -1 P Lawrie (Sco); Level: P Casey (Eng); +1 J Day (Aus); +2 J Rose (Eng); +6 D Willett|
Thomas Pieters holed a 31-foot birdie putt at the last to take a first-round lead at the Bridgestone Invitational.
Belgium's Pieters, 25, scored a five-under-par 65 at Firestone Country Club in Akron, Ohio and is one shot ahead of Scotland's Russell Knox.
Jordan Spieth was a shot further back, alongside Rory McIlroy, who was competing without caddie JP Fitzgerald.
McIlroy ended a nine-year partnership with Fitzgerald this week, with Harry Diamond taking his place temporarily.
Northern Ireland's world number four carded five birdies and two bogeys, the second coming at his final hole.
"It was good, a little weird at the start," McIlroy said.
"I'm taking a little bit more responsibility on myself and there were a couple of times where I probably should have hit another club, but that's on me, not anyone else.
"I'd much rather be frustrated at my own decision than someone else's. It's great to have my best mate on the bag and we're just having a good time.
"It was strange the first couple of holes but I stuck to it today and played pretty well. I guess it's the start of the next chapter in my career and we'll go from here."
Defending champion and world number one Dustin Johnson is one shot behind McIlroy after carding a two-under-par 68, while former Masters champion Danny Willett's miserable form continued with a 76.
McIlroy split with Fitzgerald after winning four majors together, saying "sometimes to preserve a personal relationship you have to sacrifice a professional one".
He has brought in Diamond, a friend since childhood, for the Akron tournament and next week's major, the PGA Championship in Charlotte.
"I just needed someone that knew me and that's why I took Harry for the next couple of weeks," he said on Wednesday.
"If something doesn't work out and Harry and I say two weeks is enough, I'll need to find someone else but I've got 10 days between the end of the PGA and the start of the Northern Trust to do that."