Waterford’s Seamus Power and Kevin Phelan shot the lights out on opposite sides of the Atlantic but it was a major battle for Rory McIlroy to kickstart his FedExCup campaign in The Barclays in New York.

Phelan fired eight birdies in an immaculate, best-of-the-season 64 in the Challenge Tour’s Bridgestone Challenge at Heythrop Park Resort in Oxfordshire.

He shares second place with America’s Shiwan Kim and France’s Damien Perrier, four strokes behind Belgian Thomas Detry, who shattered the course record with a 12 under par 60.

On the Web.com Tour, West Waterford and Rio Olympics star Power hit 10 birdies in a seven under 64 at Pumpkin Ridge in Oregon to lie just a shot behind leader Ryan Brehm in the WinCo Foods Portland Open presented by Kraft Heinz,

Power got back  from Rio de Janeiro eight days ago where he represented Ireland in the Olympics and tied for 15th.

“It was fantastic. I couldn’t have asked for more,” Power told the Portland Tribune of the Olympic experience. “Everything about it was a great couple of weeks.”

Power’s favourite parts of being at and in the Games, off the course, included getting to see tennis stars Rafael Nadal and Venus Williams in the athletes’ village and watching badminton and swimming.

“The badminton in person was more impressive than I thought it would be. It was amazing,” he said.

The 6-3 Power, 29, played college golf for East Tennessee State. He isn’t backing off this week, even with a PGA Tour card in hand.

“You can never have enough good finishes,” he said. “You’re trying to do two things — build momentum into the next season (and) get as high of a card as you can so you can give yourself as many starts as possible.”

But it was "only" a level par 71 for McIlroy, who had 31 putts and missed several from short range on the infamously tough Black Course at a blustery Bethpage State Park in the opening round of The Barclays.

• The Barclays - Scoreboard
• WinCo Foods Portland Open presented by Kraft Heinz
• Bridgestone Challenge

"Yeah, it was okay," McIlroy said. "I think everyone saw it was difficult conditions out there. Felt like I probably could have been a few better, missed a couple of short ones.

"I hit the ball pretty well from tee-to-green. I think anything under par today, in the afternoon especially, is a good score. Have to get back out there tomorrow in better conditions with the greens a little bit better and try to shoot something in the 60s."

The Holywood star lurched through his first nine holes in two over par 37 and was battling to catch clubhouse leaders Patrick Reed and Martin Laird, who opened their accounts with five under par 66s to lead by one stroke from Argentina’s Emiliano Grillo, Kevin Chappell and world No 8 Rickie Fowler.

McIlroy is more concerned with improving his world No 5 ranking and moving up from 36th in the FedExCup standings but his new Scotty Cameron putter was only working intermittently.

Starting on the tougher back nine, the 27-year old Co Down man missed a five footer for birdie at his fifth hole and promptly bogeyed the next two, three putting the 15th from nearly 50 feet and then missing a seven footer for par at the index one 16th where he hit a poor drive and came up short in sand with his approach.

"I worked pretty hard on my game the last week or so," said McIlroy, who has changed putter and his way of putting in conjunction with Phil Kenyon, it appears. 

"Tee-to-green the rust wasn't really there. But on the greens, I am trying something new with my putting and I felt a little tentative at the start. I left a couple short early on and then I missed the short one on the fourth hole today. I struggled to get into the rhythm of it but I stayed with it and stayed patient. Felt like even par was a fair reflection of how I played."

While Graeme McDowell had to putt superbly to salvage a one over 72 that did his hopes of a Ryder Cup wildcard little good, McIlroy was less than clinical with the blade or his wedges.

He tugged one into sand at the 18th but splashed out to 18 inches to turn in two over, then set about clawing his way back to one under with two to play

A short iron to four feet set up McIlroy’s first birdie of the day at the second and he then got up and down from the fringe for another at the short par-five fourth before hitting a long range bunker shot close at the par-five seventh.

A referee had to be called when McIlroy's ball moved almost imperceptibly as he addressed it at the fourth but he was deemed not to have caused it to move.

He explained: "Yeah, I addressed my ball, so I put my putter behind it, but with the wind, that's a very exposed green. And with these poa greens, as well, sort of what happened to Dustin at the U.S. Open, as well, any tiny bit of movement, whether it's wind or even pressure of your feet -- not really making the ball move but told the ref what happened, and he said with the wind and everything, I don't think you caused the ball to move. I just played it from where it was."

When he birdied the par-five seventh with a superb bunker shot to 18 inches, he was one under of the day and a shot outside the top 15. But he the three-putted the par-three eighth from 15 feet, lipping out from four feet for par.

"It is definitely a long term process," McIlroy said of his putting on Sky Sports. "I had to think about my philosophy on putting and basically try something different and something that I know will work as long as I give it the time and do the necessary work on the greens.

"I missed a short one for birdie on the 14th and another one there obviously. My misses on the putting green are left and my misses on the golf course are right so I just need to figure that out a little bit and I'll have another chat when I get in and see if I can work on something going into tomorrow."

Asked if the end of the season, the FedExCup and the Race to Dubai meant it was "a huge few weeks" he said: "It is. I want to move up from 30-someting in the FedExCup and at least give myself a chance to win the FedExCup going into Atlanta. And then you have the Ryder Cup after that and then the Race to Dubai after that.

"I am potentially playing nine of the next 12 weeks so there is still lot to play for, even though the majors are gone. That was a nice three weeks (off) to reassess my goals and see what I have to play for this year and there is still quite a lot.

"I feel like there are world ranking points up for grabs. I can climb that again. There's the Race to Dubai, Ryder Cup. There is still a lot of golf left this year."

Bridgestone Challenge

60 T Detry (Bel) ,

64 Kevin Phelan (Irl), S Kim (USA), D Perrier (Fra), 

65 A Tadini (Ita), A Knappe (Ger), W Harrold (Eng), M Pavon (Fra), A Saddier (Fra),

66 R James (Wal), J Smith (Eng), T Lawrence (RSA), B Paolini (USA), J Senior (Eng), O Bergqvist (Swe), S Brown (Eng), J Garcia Pinto (Esp), A Björk (Swe),

67 M Ovesen (Den), P Relecom (Bel), P Oriol (Esp), E Cuartero Blanco (Esp), S Tiley (Eng), J Guerrier (Fra), B Hafthorsson (Isl),

68 M Armitage (Eng), M Kinhult (Swe), S Campbell (Eng), T Pulkkanen (Fin), W Besseling (Ned), J Doherty (Sco), J Wrisdale (Eng), R Fox (Nzl), T Bakker (Fin), E Dubois (Fra), S Hodgson (Eng), R Saxton (Ned), J Stalter (Fra), K Samooja (Fin), A Velasco (Esp), B Ritthammer (Ger), D Huizing (Ned), C Koepka (USA), S Gregory (am) (Eng),

69 Mark Murphy (Irl), Ruaidhri McGee (Irl), 

70 Brian Casey (Irl), Gareth Shaw (Nir), Reeve Whitson (Nir), Chris Selfridge (Nir).