Glen Johnson continues to amaze.

The former light heavyweight champion, having dropped from 175 pounds to 168 at 41, stopped Allan Green 36 seconds into the eighth round in Super Six tournament fight on the Juan Manuel Lopez-Rafael Marquez undercard Saturday in Las Vegas.

Green fell victim to two blows, a right behind the ear and another right to the face as he was going down. The loser complained to referee Robert Byrd as he lay on the canvas, apparently because of the first punch, and was able to stand but Byrd decided he was unable to continue.

Green (29-3, 20 knockouts) was leading on two cards by the same score (67-66) and losing on the third (68-65) at the time the fight was stopped.

With the victory, Johnson (51-14-2, 35 KOs) earns a spot in the Super Six semifinals.