CHASKA, Minnesota, August 13, 2009 (AFP) - Padraig Harrington is being pushed to the limits once more by Tiger Woods and after cracking under the pressure last week, the Irishman is excited for a rematch to defend a major title.

Three-time major champion Harrington fired a four-under par 68 on Thursday to stand second, one stroke behind pace-setting playing partner Woods after the opening round of the 91st PGA Championship at Hazeltine.

"It's always a good sign if you are matched up with Tiger. It means you are in the right place," Harrington said. "If you don't want to be in that spot, you shouldn't be playing golf.

"It pushes you. You have to go to a new level. That's what I like. There's no point in being cautious or playing safe. Tiger brings that out. He pushes you a little bit more. You have to go for your shots if you want to compete."

Just four days earlier, Woods and Harrington battled down the final holes of the Bridgestone Invitational before a nightmare 16th hole turned the Irishman's one-stroke lead into a three-stroke deficit and sealed his runner-up fate.

"It wasn't great but it wasn't a catastrophe," said Harrington, who warned Woods after the loss that "We will do battle many times again."

But that last-pairing duel took something from Harrington for this one. He was tired and did not practice Tuesday.

"I am drained. No question about that. Last week took an awful lot out of me," Harrington said. "My preparation has been poor. Most of my preparation this week has been about getting my mindset right.

"I'm happy with the score. It's a little tough when you are coming back to defend. There's a little more spotlight and focus so 68 is a good start."

But Harrington knows he has the major roadblock to a major repeat in front of him in Woods.

"There is a factor about the fact Tiger is five-under and looks like he's playing awfully well and looks like he could move away," Harrington said.

"The key will be obviously if he's moving away to make sure I'm moving away with him. It was tough last Sunday but I don't want to give him a three-shot start on Sunday."

The rivals enjoyed a more casual mood in round one of the 7.5 million-dollar event than they had when fighting for a title.

"We were a lot more relaxed and we chatted away today. Totally different atmosphere," Harrington said. "Sunday is a business day. Thursday is let's get into the tournament."

Harrington has recovered the form which brought him a second British Open crown and his first PGA Championship title last year. Worries in his swing have led to a sub-par season until last week.

Now Harrington has realized he has been lagging his arms on his swing and solving that problem allows him to face others.

"It's not that I have it sorted out, but my mind is a lot more at ease. I know what I need to do," Harrington said. "I'm comfortable to spend more time on my short game and things like that and that's obviously paying dividends."

Harrington was headed for practice bunkers to try and address a weak spot that he felt might have kept him from the lead in round one.

"I had two poor bunker shots. I just misjudged them. That's two shots I let away from the round," Harrington said. "If I'm going to look for places to improve the next three days that is one of them."