Fort Worth, TX (SportsNetwork.com) - Kevin Na fired a 4-under 66 in Friday's second round and that was good enough to give him a 2-shot lead heading into the weekend at the Crowne Plaza Invitational.

Na, who shared the first-round lead with world No. 2 and Masters champion Jordan Spieth, this event's 2013 champion Boo Weekley and Ryo Ishikawa, finished 36 holes at 10-under-par 130. Na is seeking his second win on the PGA Tour and first since 2011.

"I had a lot of fun today," Na said. "I was making a lot of putts, hitting some great shots and the crowd was so nice. They were cheering me on, I felt the support and it brought a lot of smiles to my face."

Ian Poulter used a 3-under 67 to take the clubhouse lead early on Friday before Na caught and surpassed him at Colonial Country Club. Poulter is alone in second at 8-under 132.

Weekley overcame a tough start to shoot a 1-under 69, putting him alone in third at minus-7. Brian Harman (66) and George McNeill (69) are one shot further back at 6-under 134.

Spieth struggled down the stretch and shot a 3-over 73, tying him for 15th at 3-under 137. Defending champion Adam Scott is tied for 25th at minus-2 following a 4-under 66.

The 21-year-old Spieth was rolling along early before a bad finish. Starting on the back nine, he made a birdie on 14 to go along with eight pars. Spieth got up and down for birdie at the par-5 first and was up to minus-8 for the week.

Starting with a bogey on No. 4, Spieth's downfall only got worse as it took him seven shots to get in on the par-4 fifth, leading to a triple-bogey. Spieth closed with three pars and another bogey on No. 8, making it five dropped shots over his final six holes.

"Yeah, 5-over on the last six, very disappointing," Spieth said. "Felt like I really had a lot of good looks today, a lot of mid-range looks ... Just a couple bad swings is all it was. It wasn't anything other than that. Disappointing, though, to come obviously from the lead to being what will be five, six, seven back going into the weekend. That's not ideal for the finish."

Na was quiet on the front nine as he wrapped eight pars around a birdie from four feet out at the par-4 sixth. The 31-year-old made the turn at minus-1 for the day and just one shot back of Poulter.

Around the turn, Na drained a 25-footer for birdie on 10 and later made back- to-back birdies from 22 and 30 feet on 13 and 14, respectively.

Now in the lead at minus-10, Na made a pair of pars from 15 before holing a 6- footer for birdie on 17 to take a 3-shot lead.

Na's lone bogey came at the last after his tee shot went right and into a creek. The dropped shot left Na with a 2-stroke lead heading into the weekend.

"I'm just going to try to have fun and I've been doing that the first two days," said Na about how he is going to approach the weekend. "Keep having fun, keep playing well and keep the foot on the gas."

Poulter made six birdies and three bogeys on his round to shoot 3-under. Weekley started with four bogeys and a birdie on No. 3 to begin his day before finishing with four gains and nine pars over his final 13.

NOTES: Na has held at least a share of the 36-hole lead six times on Tour, one of which resulted in his win at the 2011 Shriners Hospitals for Children Open ... Poulter has not won on tour since the 2012 WGC-HSBC Champions ... In the event of a win this week, Weekley will have four tour wins at just two events. He has won the Heritage twice (2007 and 2008) ... Ishikawa (74) is tied for 25th at 2-under 138 ... With the cut falling at 1-over 141, 80 players advanced to play the weekend.