There was a little sweet but plenty of sour for Rory McIlroy on his return to regular competition after a frustrating opening effort in the WGC – HSBC Champions event in Shanghai.

McIlroy could manage just two birdies in a one under par 71 that left him trailing seven shots from Sweden’s Rikard Karlberg who posted an eight-under par 64 on a rain-softened Sheshan course.

American Rickie Fowler is in second spot shot a 65 and with Scotland’s and defending champ, Russell Knox in a group with a six under par 66.

McIlroy is contesting the $US 9.5m event for sixth occasion and with his best effort being a pair of fourth place finishes on debut in 2009 and then two years later.

But not for a first time this season, there was a clear touch of frustration in his tone.

A little sweet but far too much sour for Rory McIlroy on day one 2016 WGC – HSBC Champions.

“It was okay but I felt like with the way I hit it, I probably could have squeezed a couple more out of the round,” he said.

“I sort of was trying to stay as patient as I could. I had a good chance for eagle on 16 and missed, but made birdie. “I then hit it in the middle of the fairway on 18, looking to hit it in two and hit it in the water, so from looking like you’re maybe going 2-under through nine and you’re back to even.

“I was then just trying to basically to shoot something in the 60s after that.  Overall, I feel I did everything okay. I just didn’t really get it going. Didn’t really get any momentum going.

“But I’ll go out there tomorrow and know that I feel like I’m playing well enough to shoot a score in the mid-60s and get myself back into it.”

However McIlroy did give the thumbs up to the  new TaylorMade M2 driver he’s put into his Nike bag.

“I felt like I drove the ball really well,” he said.  “Look, I’ve been driving the ball well anyway, but yeah, it was nice to see the ball flying where it was going.

“I would say I would have been level without them and maybe a little bit behind before, and I was hitting it by both of them, so can only be a positive.

“Especially when conditions are like this and it’s so soft, it goes a long way in the air.

“Hopefully that can be to my benefit over the next few days.”

Shane Lowry, and the only other Irishman in the field, carded a two over par 74 that included two birdies and twice as many bogeys, to be sharing 57th place in the 78-player event.

And the Ryder Cup winning duo of Patrick Reed and Jimmy Walker failed to bring their Hazeltine victory form to Shanghai signing for 78s.