A revived Padraig Harrington reignited his US PGA challenge at Oakland Hills today with a stirring performance at Oakland Hills. Harrington's charge on the back nine moved the Open champion to within three strokes of the lead and touching distance of a second major of the year.

Harrington had complained of mental fatigue in the wake of Friday's disappointing second round but yesterday's lengthy delays appear to have rejuvenated the Dubliner.

And while the overnight storms may have made the Oakland Hills 'Monster' a little less frightening, Harrington played with renewed vigour to storm up the leaderboard.

Starting the day on five-over, and with eight holes of his third round completed yesterday, Harrington's round caught fire on the 13th where he posted the first of four successive birdies.

A bogey a the last may have cost the British Open champion a share of the course record but on one-over Harrington is just three behind leader Ben Curtis.

"It was a slow start to the second part of my round but the four birdies in the middle got it going and I holed some putts in that run which was nice to see happening and get some feeling on the greens, Harrington said after his round.

"I am four behind at the moment and I would take that as long as there are not 20 guys between me and three under. You don't know what is going to happen in the afternoon.

"I caught six up in the Open in 2007 and as long as there are not too many bodies ahead of you, you can make up quite a big amount in the last round of a major."

Curtis shot a two-under-par 68 to grab a one-shot lead heading into the last 18 holes on a marathon day. Curtis stood at two-under-par 208, one stroke better than fellow American JB Holmes, the overnight leader, and Sweden's Henrik Stenson.

Because of the downpours and lightning that hit the Detroit suburb on Saturday and suspended third-round play, the leaders were having to navigate 36 holes on Sunday.

The leaders are scheduled to begin at 7.10pm Irish time. Players will compete in threesomes and go off from the first and 10th tees in order to fit in the final round.

Stenson birdied the 18th to reach one-under-par 209 with a round of 68, while Holmes bogeyed the last to complete an even-par 70.

Curtis, the 2003 British Open winner, also bogeyed 18 after hitting his tee shot into a bunker but had built up a strong round on the rain-softened course with four birdies over his first six holes during the chilly morning.

Curtis, Stenson and Holmes were among six players who did not hit a tee shot on Saturday, when play was called off after a delay of more than four hours and only 25 of the 73 players left in the field were able to finish the third round.