A resurgent Jordan Spieth moved firmly into contention in the US PGA Championship following a soggy start to the second round at Baltusrol.

Two-time major champion Spieth was birdie-free for much of the first day, but picked up two shots in his final three holes to open the tournament with an even-par 70.

As one of the earlier starters in round two, Spieth was held up on Friday when heavy rain forced a brief suspension in play.

Yet the young Texan - seeking to regain the spectacular form he showed in 2015 - had soon moved to within one stroke of overnight leader Jimmy Walker, birdies at the 10th, his first hole, 11th, 13th, 17th and 18th offsetting a solitary dropped shot on the 12th.

Patrick Reed and Webb Simpson had moved into the group at three under, one behind Spieth, but Martin Kaymer and Open champion Henrik Stenson were heading in the wrong direction.

Kaymer, who began the day one off the pace in joint-second alongside Ross Fisher and Emiliano Grillo, slipped back to two under through 11 holes, while Stenson was also two over for his round and one under overall as he approached the turn.

U.S. Open champion Dustin Johnson appeared certain to miss the cut after losing further ground on the back of his first-round 77.

Walker, Fisher and Grillo were among Friday's later starters.