The Irishman is tied for seventh place, three shots behind early pace-setter Tiger Woods after a 25 foot birdie putt at the last.

But while Harrington produced a solid start his compatriots Darren Clarke and Paul McGinley struggled, shooting 74 and 75.

"I'm very pleased, obviously, that I birdied the last," said Harrington.

"I played nice enough through the round and I felt 70 was about the right score, so it was good to birdie the last.

Harrington said the course, was proving to be a real challenge for all the players.

"You stand in every tee box and you have got to hit the fairway to give yourself a chance and once you have done that then you are left with a tough shot to the green," he said.

"You are under pressure at all stages. I hit a lot of fairways today and only hit it in the heavy rough twice.

"I think in benign conditions, level par for the tournament is a good score. There's only a handful of guys under par."

Nick Faldo, who also shot a 70, said the enthusiastic New York crowd meant that he had to use all his powers of concentration.

"We just have to bed down an keep playing," he said.

"It takes a lot of concentration with the crowds going nuts so I have just got to keep doing what I have been doing today."