PITTSBURGH — John Huston shot a 5-under 65 on Thursday to take the first-round lead in the Senior Players Championship.

Huston started on No. 10 and was even par halfway through his round before making a big move on the front nine at soggy Fox Chapel. Huston shot 5-under 30 coming in, including four birdies and an eagle on the short par-4 seventh. The 52-year-old Huston missed three months this season because of lower back problems.

Fred Couples, Duffy Waldorf, Fred Funk and Russ Cochran were a stroke back in the third major on the Champions Tour schedule. Tom Pernice Jr. had three straight birdies to start his round and led a group of five players at 67.

The start of play was delayed nearly five hours because of heavy rain.

When the sky cleared the soft greens allowed players to be aggressive on the typically treacherous greens at the rolling course located a few miles up the Allegheny River from downtown Pittsburgh.

Nobody did more damage than Huston.

The seven-time PGA Tour winner got his round going with a tap-in birdie on the par-5 18th, kickstarting a stretch where he made five birdies in a span of seven holes, including a 40-footer on No. 6. He capped the run by driving the green at the 295-yard par-4 seventh and sinking the 25-footer for eagle to vault him into the lead.

The putts gave Huston a welcome confidence boost after spending three months getting treatment on his back. He returned last week and finished 32nd at the Encompass Championship then took a couple days off to rest up. He only found the fairway nine times but was bailed out by his putter. Huston came into the tournament ranked 54th on tour in putting average but had little trouble once things started falling.

Couples, searching for his first victory of the season, put together three birdies on the back nine, including one on the 18th that pulled him within a shot of the lead. Couples finished fourth at Fox Chapel last year, faltering on the weekend to finish four shots behind winner Joe Daley.

Points leader David Frost, who edged Couples by a shot at the Regions Tradition three weeks ago to capture the first major of his 32-year career, bounced around all day before joining a large group at 68.

Newly minted Hall of Famer Colin Montgomerie began his Champions Tour career with a steady 1-under 69. The 31-time winner on the European Tour started a little shaky, flying his approach shot on the 10th hole over the green. He scrambled for par and missed just one more green the rest of the day.

Montgomerie's debut was pushed back several hours after strong overnight storms left portions of the 6,696-yard course under water. Twice players were told to warm up only to be notified of a delay before things got going just after noon. Officials sent players off both the first and 10th tees, invoked the lift, clean and place rule and moved the tees up on a handful of holes to speed things along.

Even the little nudge forward didn't always help. Tee shots plugged into fairways and approach shots went nowhere, helping bunching the field. Over half of the 81-player field finished at even or better, creating little separation.