The 24-year-old Thai star has surged to the top with 100,779 points from 17 tournaments played, replacing China’s Shi Yuqi who has 100,567 points from 11 tournaments, reports the Bangkok Post.
Denmark’s Anders Antonsen (93,729), Indonesia’s Jonatan Christie (84,174) and France’s Christo Popov (81,925) round out the top five.
Kunlavut’s return to the summit of the sport was confirmed when he reached the quarter-finals of the All England Open - a Super 1000 event - in Birmingham last Friday.
He previously fell at the last 16 stage of the sport’s oldest tournament on six occasions.
Kunlavut lost to eventual winner Lin Chun-yi of Taiwan in the semi-finals. Lin beat Lakshya Sen of India in the title match on Sunday.
This is Kunlavut’s second stint as world No.1. The Thai ace reached No.1 in June last year. His reign, however, lasted just seven weeks.
Kunlavut has so far won one title this year at the season-opening Malaysia Open - a Super 1000 event - in January.
Ratchanok Intanon remains Thailand’s highest-ranked women’s singles player at No.7 with 69,964 points, followed by All England Open quarter-finalist Pornpawee Chochuwong at No.8 with 67,221 points. South Korea’s An Se-Young is at No.1 with 115,770 points.