One day after becoming the youngest player to shoot 59 on the US PGA Tour, Justin Thomas made more history this afternoon at Waialae Country Club.

The 23-year-old shot 6-under 64 in the second round of the Sony Open in Hawaii, where his 123 total is a record for the lowest 36-hole score on tour.

The previous mark was 124 held by three players, most recently Jason Day at the 2015 BMW Championship.

“I just felt like it was another round of golf and I need to try to build on my lead and see how low I could go today,” Thomas said.

After a slow start, he did just that, rattling off four straight birdies around the turn to build momentum.

Thomas made a sloppy bogey at the 13th, failing to get up and down from a greenside bunker, before bouncing back with another birdie at 15. He made another bogey from the bunker at 17 but atoned for the mistake by reaching the par-5 18th in two and rolling in the eight-foot putt. It was the second straight day that he closed with an eagle.

Through the first two weeks of 2017, no one has been better than Thomas, who is coming off a win last week at Kapalua. In his first six rounds of the year, he is combined 39 under.

“It’s definitely the best [golf] of my career,” Thomas said. “I definitely haven’t shown the world my best golf. I haven’t even shown the world great golf, or consistent, great golf.”

Through two rounds at Waialae, however, he has been just that. Thomas leads the field in strokes gained-tee to green and his 64 on Friday tied for the second-best score of the round behind only Zach Johnson’s 61.

“I think I’m getting more confident and I’m improving, too,” said Thomas, who also won last October, successfully defending his title in Malaysia. “I think I’m just trending up and hopefully — wanting to show everyone in the world what I have.”