Updated

Defending champion Phil Mickelson rocketed into a three-way tie for the lead at the Houston Open in Humble, Texas on Friday when the rain-delayed first round was finally completed.

The American left-hander, one under with 15 holes remaining when play was suspended on Thursday after thunderstorms swept across Redstone Golf Club, carded a seven-under-par 65 to join Carl Pettersson and Angel Cabrera at the top.

Swede Pettersson and Argentina's Cabrera had both completed their rounds in calm, overcast conditions on Thursday before play was halted for the day.

"I played really well," Mickelson told reporters after mixing eight birdies with a lone bogey. "There was no wind. The conditions were ideal. The greens were immaculate.

"If you could get it on the surface, you felt like you could make some putts," added the four-times major winner, who totalled only 22 putts in the opening round.

Mickelson's only blemish came at the par-five 13th where his ball picked up mud on the rain-softened fairway.

"There's not much you can do about stuff like that," said Mickelson, who won last year's event by three strokes after closing with a sizzling seven-under-par 65.

"Every shot in the fairway had a bunch of mud on it. It was tough maneuvering around there."

More than an inch of rain saturated the course on Thursday and tournament organizers allowed the players to lift, clean and replace their balls in the second round.

Americans Ricky Barnes, Jeff Maggert and John Huh, plus Britain's Greg Owen, opened with 66s while last year's PGA Championship winner Keegan Bradley and PGA Tour veteran Fred Couples were among a group of seven players knotted on 67.

(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Julian Linden)