Andy Hiraoka could’ve taken out Shun Akaiwa earlier Tuesday, but he eventually got the job done.

The unbeaten junior welterweight contender stopped Akaiwa in the fifth round of their fight on the Naoya Inoue-Nonito Donaire undercard at Saitama Super Arena in Saitama, Japan. The left-handed Hiraoka (20-0, 15 KOs) dropped Akaiwa in the first round and hurt him again in the fifth round, which prompted referee Takeru Okaniwa to stop their scheduled 10-round bout.

The official time of the stoppage was 1:24 of the fifth round. Tokyo’s Akaiwa (7-4-1, 5 KOs) was on his feet when their fight was halted.

Yokohama’s Hiraoka, 25, has won six straight bouts by technical knockout. After flooring Akaiwa in the first round, Hiraoka allowed his opponent to get back in the fight over the ensuing three-plus rounds.

A right uppercut by Hiraoka made Akaiwa stumble backward with just over two minutes to go in the fifth round, though. A second right uppercut by Hiraoka wobbled Akaiwa again and made him move toward the ropes.

Hiraoka then landed a thudding left hand that made Okaniwa step between them to prevent Akaiwa from taking more punishment.

Hiraoka landed back-to-back left hands about 50 seconds into the fifth round. Akaiwa landed a right hand that made Hiraoka back away from him with 35 seconds to go in the fifth round.

A left hand by Hiraoka landed with just over a minute remaining in the fourth round.

Hiraoka fought his hands by his side for much of the third round. A straight left hand by Hiraoka made Akaiwa back up with just over a minute on the clock in the third round.

A right hand by Akaiwa turned Hiraoka around and made him reset his feet just after the halfway mark of the second round. A left uppercut by Hiraoka stopped Akaiwa in his tracks with 45 seconds to go in the second round.

Another right hand by Akaiwa made Hiraoka take a step back late in the second round.

Hiraoka landed a left uppercut and made Akaiwa stumble backward about 1:15 into the first round. His right glove touched the canvas, which counted as a knockdown with 1:42 on the clock in the opening round.

Akaiwa, who suffered the second knockdown of his career, landed a right hand after he got up that made Hiraoka move away from him.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.