Hideki Matsuyama finished the British Open in a tie for 18th place at 8-under-par 280 on Monday, seven strokes behind the winner, American Zach Johnson.
Johnson defeated Australian Marc Leishman and South African Louis Oosthuizen over a four-hole playoff.
On the final day of the weather-hit major, Matsuyama carded three birdies on the front nine and added another on No. 10, but missed a three-foot par putt on No. 12 before hitting into rough on No. 15 and to a bunker on No. 16 for three bogeys, recording a 1-under-par 71 for two days in succession.
"I lost my momentum (at No. 12). If only I had putted more calmly," said Matsuyama, who needed a second round-low 24 putts, but overall was let down on the greens, averaging 30-putts per round for the tournament.
"I'm still missing something and that's why I can't win. I couldn't tough it out and it is frustrating, and my putting is the prime reason for that.
"I putted really well just one day. If I can do that for two or three days, I feel I can win," said the 23-year-old, whose lack of polish with his putter saw him finish 18th at the U.S. Open in June.
He added: "I had to better my score after No. 10 by three or four to win. I have to be able to hone my mental strength and technique while competing for titles."