In the first round match against Antti Vikstrom of Finland, the 29-year-old Khairul staged a remarkable comeback from 1-5 down to seal a sensational 6-5 win at the Yumenoshima Park Archery Field in Tokyo
Khairul came out tops in the one-arrow decider by shooting a 10 to beat Vikstrom's nine after the match ended in a 5-5 draw (26-29, 28-28, 26-27, 28-22, 25-13).
Khairul returned shortly to overcome China's Wang Dapeng in almost a similar fashion in the second round.
The regulation play finished 5-5 (25-28, 28-28, 27-26, 29-26, 26-27) before Khairul kept his nerves in check to hit the bullseye once again when it mattered most to triumph 6-5 against Dapeng.
Khairul is now one win away from matching his previous best quarter-final outing in London 2012.
He will know who he plays against in the last 16 later this evening. Barring any upset, Khairul is expected to face world No. 5 Kim Woo-jin of South Korea. The last 16 knockout will be held on Saturday.