'It feels really good,' said Tway. 'A lot of great players have won this.'
Tway never trailed in Saturday's 36-hole final. He won four of his first nine holes, and took a 4-up margin into the break between 18 holes.
Tway parred the 19th and 22nd holes to extend the lead to 6-up, but Johnson had some fight. Johnson birdied the ninth and 10th holes in the afternoon session, but missed makeable birdie tries at the next two holes to effectively end his run.
Tway halved the next four holes, then the match came to its end at No. 15. Johnson landed in a greenside bunker and could not get up and down for par. He then conceded Tway's 15-footer for birdie to give Tway the win.
'He really won the match one the first nine holes this morning,' admitted Johnson. 'He was 4-up and that's where it stayed. I guess I wasn't quite ready to play. He made all of his putts there and I got a little discouraged.'
Tway did something his father Bob, the 1986 PGA Champion, never managed in his amateur career. The elder Tway failed to make it out of the first round of match play in both of his appearances in this event, but the younger Tway was diplomatic about the family wins.
'He didn't win this tournament, but I haven't won any of the ones he's won,' said Kevin.
The Junior Amateur, for golfers age 17 and younger, is one of 13 national championships conducted annually by the United States Golf Association.