FORTH WORTH, Texas: As Masters champion Jordan Spieth imploded late, Kevin Na withstood tough, rainy conditions to hold a two-shot lead over Ian Poulter after two rounds of the US PGA Tour’s Crowne Plaza Invitational.

Spieth’s North Texas homecoming took a turn for the worse on Friday as he fell victim to Colonial Country Club’s “Horrible Horseshoe” of holes three, four and five.

The 21-year-old world number two teed off on 10 and had two birdies without a bogey through his first 12 holes and topped the leaderboard at eight-under.

But a bogey at the par-three fourth was followed by a triple-bogey seven at the par-four fifth, and Spieth dropped one more shot at the par-three eighth in a three-over 73 that left him on three-under 137 — seven shots off Na’s 10-under total of 130.

Na, who shared the overnight lead with Spieth, Boo Weekley and Japan’s Ryo Ishikawa, had five birdies before his only bogey of the day at his final hole in a four-under 66.

That gave him a two-stroke cushion over England’s Poulter, who had six birdies in his three-under 67 for 132.

Weekley was alone in third after a 69 for 133, with George McNeill (69) and Brian Harman (66) sharing fourth place on 134.

Spieth called his day “very disappointing.”

“Just a couple of bad swings is all it was,” said Spieth, whose three-wood off the tee at the fifth sailed out of bounds to the right.

He ended up two-putting from 20 feet for the triple-bogey.

“That hole is hard,” Spieth said.

Spieth played his last few holes in some heavy rain, struggling at times to hang onto his irons.

“You know what? I should have done a better job of it,” he said of coping with the conditions.

With more severe weather forecast for Saturday afternoon, third-round tee times have been moved up in hopes of getting the round completed before the worst weather arrives.

Poulter heads into the weekend with perhaps something to prove.

The Englishman, who has never won a stroke-play event on the United States, was voted along with Rickie Fowler the most “overrated” players on the PGA Tour in an anonymous poll of players conducted by Sports Illustrated last month.

Fowler responded by winning the Players Championship two weeks ago.

“He’s taken care of his business. It’s time for me to take care of mine,” Poulter said.

A win this week would also justify Poulter’s decision to forego the European Tour’s flagship event at Wentworth this week.

That move sparked some criticism in Europe, although he’ll be able to fulfill his European Tour requirement regarding home tournaments at the new British Masters in October.

Record-braking youngsters chase Choi in Incheon

South Korea’s Choi Jin-Ho hung onto his lead after the third day of the SK Telecom Open on Saturday, but with a pair of youngsters snapping at his heels with record-breaking rounds at the course in Incheon.

Choi, the overnight leader, shot a two-under-par 70 to maintain his top spot on the leaderboard — but only just.

One shot behind was 19-year-old compatriot Wang Jeung-Hun who fired a course record 63 to surge into joint-second place with another Korean Kang Sung-Hoon, who carded a 69.

Just one more stroke back was 21-year-old Lee Soo-Min who also charged through the course with a 63.

“I didn’t watch the leaderboard and it was probably just as well looking at those scores,” said Choi, who turns 31 next week.

Wang and Lee’s rounds beat the previous course record of 64.

It was a consistent performance by Choi, who is enjoying only his third tournament back on tour since finishing a 20-month stretch of military service, which is mandatory for every able-bodied South Korean male between the ages of 18 and 35.

Wang’s record round included an eagle, eight birdies and one bogey and, despite his youth, he has already shown he is capable of competing for top place finishes.

Wang triumphed in the Mission Hills Haikou Open last year by cruising to a 10-shot victory on the PGA Tour China.

Defending champion Kim Seung-Hyuk from Korea carded a 67 on Saturday to leave him three off the lead.