Julian Jackson dropped former champion Buster Drayton flat on his back with a left hook Saturday to retain his World Boxing Association junior middleweight title on a knockout with three seconds left in the third round.

Jackson decked Drayton with a right to the chin in the second round, but the challenger rallied late in the second and early third rounds.Drayton opened the third by pelting Jackson to the head. But with about a minute left in the round, Jackson found the range with hard rights to the head and body.

Jackson backed Drayton up then caught him with a left hook on the jaw. Drayton toppled backward and ringside doctors jumped in the ring signalling an end as referee Tony Perez' count reached five.

Jackson, 34-1 with 31 knockouts, took control early with hooks to the body while Drayton, 36-11-1 did nearly nothing in the first round.