Pantoja (29-5) was making his third title defense since winning a split decision over Brandon Moreno at UFC 290 on July 8, 2023.
Asakura (21-5) was making his UFC debut, but was no match for Pantoja, who closed a -275 favorite at BetMGM Sportsbook.
Pantoja's far superior skills on the mat outweighed Asakura's hard-hitting reputation. After a brief scramble to better position himself, Pantoja got Asakura's back, put him in a body triangle, and then choked him out.
Originally scheduled to fight in the main event until welterweight champion Belal Muhammad pulled out because of a bone infection in his foot, No. 3 Shavkat Rakhmonov (19-0-0) defeated seventh-ranked replacement fighter Ian Machado Garry (15-1-0) by unanimous decision in the co-main event. Rakhmonov, who closed as a -400 favorite, was taken to a decision for the first time in his career.
After a three-round heavyweight bout, No. 2 contender Ciryl Gane (13-2-0), who went off as a 4-to-1 favorite, earned a split decision over No. 3 Alexander Volkov (38-11-0).
In a featherweight bout, No. 13 Bryce Mitchell (17-3-0) stopped Kron Gracie (5-3-0) 39 seconds into the third round after he followed a powerful body slam with a thunderous forearm to the head. Mitchell closed a massive -1000 favorite.
After the betting market drove the closing price down to +115 on underdog Dooho Choi (16-4-1), he delivered with a stoppage at 3:21 of the third round after putting Nate Landwehr (18-6-0) in a crucifix, and referee Chris Tognoni stopped the scheduled three-round featherweight bout.
Two notable matches earlier in the night included former champions bantamweight Aljamain Sterling and middleweight Chris Weidman.
Sterling (24-5-0) lost by decision to Movsar Evloev (19-0-0), who has the longest active streak in the UFC featherweight division at eight.
Eryk Anders (18-8-0) topped Chris Weidman (16-9-0) by way of TKO at 4:51 of the second round.