The world number five shot a bogey free 68 (-4) to lie two behind fellow Swede Johan Carlsson
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The Open Champion parred the first 10 holes before birdies at 11, 12, 15 and 18 to get into the clubhouse at four under.
The Swede yesterday referred to the new-look West Course as 'fiddly' but did say his game is getting closer after a poor start to 2017 by his standards.
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He ends day one two behind world number 386 Johan Carlsson who shot a 66 despite bogeying the par-5 last.
Italian Francesco Molinari lies one behind Carlsson at five under after an opening bogey.
He then made six birdies including four in his back nine of 33.
Also at five-under is Scott Jamieson who carded a bogey-free 67 which was matched by Thailand's Kiradech Aphibarnrat.
He's one ahead of nine players at four under including Ryder Cup star Thomas Pieters, world number 13 Alex Noren and 2015 WGC-Bridgestone Invitational winner Shane Lowry.
Wentworth's own Ross Fisher is also at four under after a 68 which included six birdies and two bogeys, which each came on par 5s.
Tyrrell Hatton is at three under after three birdies in his last seven holes, Lee Westwood is at two under after parring the last 11, and defending champion Chris Wood, Danny Willett and Justin Rose are all at even par.
GM Playing Editor Wood bogeyed the last and blamed his score on a poor day on the greens.
"I couldn't hit the hole from three feet," said the Bristolian.
"I'm pretty disappointed and not in the best frame of mind now."
