Padraig Harrington is in danger of missing his second successive cut after a disastrous finish to his Deutsche Bank Championship first round. Four dropped shots in his last two holes left the Dubliner bottom of the field at the Boston TPC and he now faces the distinct probability of missing next month's Tour Championship.

Among the early starters, the Dubliner had been cruising at level par but a bogey at the 17th was swiftly followed by a triple bogey eight at the last as he finished on four-over.

Even though he has won two majors this year, Harrington may still not make the Tour Championship such is the way the PGA Tour's points system punishes players for missing the cut in the four-event FedEx Cup play-off series.

FedEx points leader Vijay Singh holds the early lead in Boston on seven-under after another strong performance. Bidding for his third PGA Tour title in five starts, the smooth-swinging Fijian delivered a master-class in approach play.

Singh made the most of calm, receptive conditions to take control of the second event in the lucrative playoff series which wraps up the Tour's regular season.

"I'm playing well," the 45-year-old told reporters after a round featuring eight birdies, a lone bogey and a total of 28 putts. "I'm coming off a victory last week and I'm just in a flow.

"I don't feel any pressure out there at the moment and I have a great attitude on the greens. I feel really comfortable."

Singh, who moved to the top of the FedExCup points list by winning last week's Barclays Classic in a three-way playoff, set up five of his birdies with approach shots to within two feet.

"I've been hitting the ball pretty much like that for the last week," the three-times major winner said. "Even on the practice range it feels good.

"The conditions today were great. There's no wind and the pins are very fair. That's why you've got a lot of guys shooting low numbers."

American Ben Curtis was among those taking full advantage, holing a 20-foot eagle putt at the par-five 18th, his ninth, en route to a six-under par 65.

That put him level with left-handed compatriot Eric Axley, one shot better than a group of six players including South African Ernie Els.

Paul Casey, meanwhile, did his Ryder Cup chances no harm when he finished strongly to card a three-under-par 68.

Casey, who is among several players vying for one of the two captain's picks on the European Ryder Cup team, made a slow start with 11 successive pars on a pleasant morning.

"I struggled for a bit. It's frustrating, because the greens were good and I just was not really making anything," Casey said.

"I finally hit one close on 12 and got the round finally going. It's nice to get off to a half-decent start."

Casey picked up further birdies at the 15th and 16th holes to trail Singh by four.

Another Ryder Cup contender, Ian Poulter, carded two early birdies but in the end a one-under 70 was not quite what he had in mind.

"One under is okay," he said. "I drove it well, hit my irons well, and I felt like I putted well, only one bogey on the card. I hit some good putts (and) a couple slipped by."

Casey and Poulter have only two days to impress European Ryder Cup captain Nick Faldo, who on Sunday will name his two wild-card choices for the team to take on the Americans in Kentucky in four weeks.

Both claimed they were trying to put the Ryder Cup out of their minds while they were on the course.

"You just have to try and concentrate on what you're doing and I had a job to do today, and that's play 18 holes," Poulter added. "I thought I did a pretty good job. I kept it out of my mind as much as I possibly could."

Vijay Singh, charged into an early one-stroke lead in the opening round of the Deutsche Bank Championship on Friday.