Rowdy Ryder Cup fans could not wait to get to Whistling Straits in Wisconsin after waiting an extra year to attend due to the COVID-19 pandemic.
The American joined Tiger Woods, Jack Nicklaus, Jordan Spieth and Rory McIlroy in the select group of players who won two majors before turning 25.
The last two U.S. Open winners are both 1 over par after the first round at Royal St. George's, along with defending champion Shane Lowry. Thomas is 2 over par.
Russell Henley and Louis Oosthuizen lead the way at Torrey Pines, with Brooks Koepka and Jon Rahm two shots adrift.
Corey Conners is the bookmakers' favorite at 7-1 after taking a two-shot lead in the first round at Kiawah Island.
Canada's Corey Conners leads by two strokes after shooting a 5-under par 67 in the first round, with Brooks Koepka and Phil Mickelson two and three shots behind.
Rory McIlroy is the bookmakers' favorite to win the second major of the season, followed by Jordan Spieth and Jon Rahm.
The second major of the season gets underway on Thursday at Kiawah Island Golf Resort in South Carolina.
Dustin Johnson missed the weekend cut, but he'll be there Sunday to don the green jacket on this year's champion. Justin Rose leads after two days and Jordan Spieth is charging.
England's Justin Rose leads the field by four shots after carding a 7-under-par 65 on Thursday, while defending champion Dustin Johnson finished a 1-over-par.
Johnson posted scores of 65 on Thursday and Saturday, becoming the first golfer to ever shoot two rounds of 65 or lower in the same Masters tournament.
First-round leader Justin Thomas tees off at 1:27 p.m. ET alongside 15-time major winner Tiger Woods.
Justin Thomas leads the U.S. Open by one shot after carding a 5-under 65 in the first round on Thursday.
Tiger Woods starts the first round of the U.S. Open at 8:07 a.m. ET on Thursday from tee No. 1 alongside Justin Thomas and Collin Morikawa.
The first round of the U.S. Open gets underway at 6:50 a.m. ET on September 17, with world No.1 Dustin Johnson set to hit his first tee shot shortly after 1 p.m. ET.
World No. 1 Dustin Johnson is the man to beat in the second major of the season, with No. 2 Jon Rahm and No. 7 Xander Schauffele among his leading rivals.
Dustin Johnson begins the final round of the PGA Tour season finale with a five-shot lead over Justin Thomas and Xander Schauffele.
World No.1 and FedEx Cup leader Dustin Johnson arrives at East Lake as the man to beat this weekend.
The FedEx Cup's top-30 ranked players all feature in the season finale of the PGA Tour season, which begins on Friday in Georgia.
FedEx Cup leader Dustin Johnson will start the season finale at 10-under, two shots ahead of world No.2 Jon Rahm.
The 15-time major winner has been paired with world No. 1 Justin Thomas and four-time major winner Rory McIlroy for the first two rounds.
Brooks Koepka is the bookmakers' favorite to win the tournament for a third consecutive time, with world No.1 Justin Thomas close behind.
Brooks Koepka posted his lowest score on the PGA Tour in four years as he took a two-shot lead at TPC Southwind.
Nine of the world's top-10 ranked golfers are in action at the WGC-FedEx at TPC Southwind in Memphis this week.
World No. 1 Jon Rahm has been paired with Rickie Fowler and Bryson DeChambeau for the first two rounds at TPC Southwind this week.