Rory McIlroy makes birdie at his opening hole. At this pace, Rory McIlroy will hit top form by Christmas. Six birdies in his opening round in his defence of the Deutsche Bank Championship at TPC Boston was impressive. Unfortunately, he also had five bogeys in what he described a “sloppy” one under 70 that leaves him seven shots adrift of a stunning Phil Mickelson and England’s Brian Davis.

Frustrated according to PGA Tour.com’s Brian Wacker, McIlroy said:

“I’m making a lot of birdies but also making a lot of stupid little mistakes. If I can cut those out, it’s a different story.”

If only.

Graeme McDowell also struggled, carding a one over 72 and told the twitterverse: “Struggled to get any momentum going this morning, shooting +1. Some rest this afternoon and get fired up for tomorrow.”

As for McIlroy, who started with two birdies in the first three holes, it was a round reminiscent of many he has played recently.

Two under early, he bogeyd the 14th after a visit to greenside sand, then three-putted from 28 feet at the par-three 16th, missing a three and a half footer.

Four birdies and three bogeys followed in a rollercoaster afternoon that also included a second three-putt - this one from 25 feet - after a poor wedge to the first (his 10th).

“The mistakes are coming from missing it in the wrong spots,” McIlroy told PGATour.com as he ended the day tied for 56th.

“It’s a bit mental but I still made six birdies, so not that much is wrong. It’s the worst it could have been.”

Compared to Mickelson, who threatened to shoot 59 after racing to the turn in 28, McIlroy looks like a man starting a season.

The left-hander totally outplayed partners Tiger Woods (68) and Adam Scott (73) thanks to another stunning day on the greens.

“I felt I played really well,” said Mickelson, who was matched by Davis late in the day. “Obviously, I putted well. I really made a lot of good putts. The greens were perfect the front nine. I saw the line and I just rolled them in. It felt really good to putt like that.”

Mickelson and Davis are a stroke clear of Kevin Stadler with Sergio Garcia (65) tied fourth and Lee Westwood, Jonas Blixt, Ian Poulter and Ernie Els all on four under.

The cut could fall at level par, leaving McIlroy and McDowell needing solid second rounds to avoid any nasty surprises in the FedEx Cup race for the third leg of the playoffs for the top 70.