Peter Bradbeer decided a couple of months ago that he needed to put more time and effort into his golf game, and the extra work paid off Monday when he finished as the medalist over 36 holes of qualifying for the 121st BMW Philadelphia Amateur Championship.

Bradbeer, 23, of Merion Golf Club, fired a 4-under-par 66 in the morning at the 1912 Club in Plymouth Meeting and followed with an afternoon 1-under 71 at Cedarbrook Country Club in Blue Bell to finish at 5-under 137, three shots ahead of runner-up Austin Barbin of Lock Nairn.

The top 32 finishers advanced to match play with Bradbeer as the top seed. Two rounds of competition will take place both Tuesday and Wednesday at Cedarbrook, with the 36-hole final scheduled for Saturday.

Bradbeer, a Bucknell graduate who won the 2017 Patterson Cup, the top stroke-play event on the Golf Association of Philadelphia calendar, missed qualifying for the Amateur by one stroke last year, part of what he called “a tough summer for me.”

“I really wasn’t focused, wasn’t prepared,” he said. “I wasn’t putting enough time and effort into it so I said to myself this offseason, I was going to put some time and effort into it, so I did.”

Bradbeer added weightlifting to his routine, which added 10 to 12 yards off the tee. He also worked with two coaches — Brian Creghan of Rolling Green on the long game, and Tim Yelverton of Old Waverly in West Point, Miss., on the short game and putting.

“My game is good,” he said. “To be able to play well, all the hard work that I’ve put in this offseason is starting to pay off. I think this is just the beginning. It’s great to be medalist, but I’m here for the big one so we’re going to get after it [Tuesday] and see what happens.”

Bradbeer carded an eagle — driving the green at a short par-4 and making a 4-foot putt — and three birdies in the morning, and three birdies in the afternoon.

Barbin shot rounds of 73 at Cedarbrook and 67 at the 1912 Club to hold second place at 140. The Maryland sophomore is the younger brother of Zach Barbin, the defending champion, who made match play at 144.