Thompson got off to a fast start, birdieing six, seven and eight, then adding another at 11 to briefly lead the tournament.
He came back down to earth at the end of his round, bogeying three late holes to finish at minus-1, four strokes off the lead.
Perhaps he was helped by playing with two Georgia alums, Harris English and Brendon Todd. They each did him one better, shooting minus-2.
Thompson’s caddie is his father, Todd, who also played golf for Georgia.
“I mean I’m nervous, but that also just comes with it,” he told the Georgia student publication Red and Black before the tournament. “This is my first major ever, you only get one, so I’m going to try to enjoy it as much as I can.”
“I got off to a great start,” he told Golf Week after his round. “I hit a lot of fairways coming out of the gate, which kind of gave me a lot of comfort at the start. Then I just missed a few fairways coming in and had to hack it out and try to get up and down. Unfortunately, I didn’t,”