What it means: Thomas started the final round four behind Lahiri, but the defending champion quickly took control of the tournament after Lahiri made a quadruple bogey on the par-5 3rd. Thomas birdied four of his first five holes – and nine of the last 10 holes dating back to the third round. From there the 23-year-old added three back-nine birdies to secure his second PGA Tour title. Thomas also became the first player to defend a title since Matt Every at the 2014-15 Arnold Palmer Invitational. Thomas joins Ryan Moore (2013-14) as players who have successfully defended at TPC Kuala Lumpur.
Round of the day: Thomas struggled in the third round, but he fixed an alignment issue and recorded his second bogey-free round of the week. He topped the next-lowest score by two strokes, and Thomas played his last 23 holes in 13 under par.
Best of the rest: Matsuyama (66) won the Japan Open last week, and he birdied 17 and 18 on Sunday to grab second place. Fathauer shot a 5-under 67 for a share of third place and his first top-10 since the 2015 Mayakoba Classic.
Biggest disappointment: Russell Knox was part of the final group with Thomas and Lahiri, but he never made a move in Round 4. Knox was seeking his third win in a year, but he bogeyed the par-5 10th and doubled No. 13 to finish with a 2-over 74 and a share of 10th place.
Shot of the day: Lahiri rebounded from his quad on No. 3 with a birdie at No. 4 and this eagle on No. 5:
Quote of the day: ''I felt like that was maybe the five biggest holes I've ever played in my life.'' - Thomas on his five-birdie finish on Saturday that kept him in contention