(Photo credit: Adam Cairns/Columbus Dispatch / USA TODAY NETWORK via Imagn Images)

Rookie Chandler Blanchet is halfway to his first PGA Tour title as he enters the weekend with a four-stroke lead at the Puerto Rico Open at Grand Reserve Golf Club in Rio Grande, Puerto Rico.

Blanchet followed his opening-round 64 with a 5-under-par 67 on Friday to move to 13 under for the event. Gordon Sargent posted a 70, losing ground but remaining alone in second place at 9 under.

Ricky Castillo (68), Blades Brown (67), Germany's Jeremy Paul (67) and Sweden's Jesper Svensson (69) are tied for third at 8 under.

Blanchet sank seven birdies to more than offset his two bogeys. He tops the field in driving accuracy (23 of 28 fairways hit in regulation) and has the fewest putts per green in regulation (1.48).

The alternate event opposite the Arnold Palmer Invitational also marks Blanchet's first made cut of the season after he missed the cut in his first five starts.

'The first part of the season, it's been difficult, for sure,' Blanchet said. 'It's no fun practicing on Saturday and Sunday and not playing and waiting five days (to play again). So will be very happy to play some golf on a Saturday and Sunday this weekend.'

Sargent started his round on the back nine and struggled to a 1-over 37 with one bogey and no birdies. A switch flipped for the 22-year-old on the front nine, when he made four birdies against one bogey.

Brown has the young Sargent beat by a couple of years. Brown turned professional at 17 and is hunting for his first tour win at 18 years and nine months old, which would make him the second-youngest winner in PGA Tour history.

'I'm excited to be playing two more days at the Grand Reserve. And a lot can happen in two days, so I'm excited for the weekend,' Brown said.

Amateur John Daly II, son of two-time major champ John Daly, shot a 67 to stay in the hunt in his PGA Tour debut at 7 under par.

'It's awesome,' he said of making the cut. 'This place has always been one of my favorites, like I said earlier, to come watch my dad play back in the day, so it's pretty cool to make it to the weekend.'

--Field Level Media