While boxing in the United States slows down around the holidays, prizefighting on New Year’s Eve has become a tradition in Japan. Two separate boxing events — in Tokyo and Osaka — closed out the year in boxing for 2012, with seven boxers rated by THE RING in action.

Headlining the card in Tokyo, WBA junior lightweight titleholder Takashi Uchiyama (19-0-1, 16 knockouts) successfully defended his belt for the sixth time, stopping previously unbeaten Costa Rican Bryan Vazquez (29-1, 15 KOs) with a brutal eighth-round assault. Referee Raul Caiz Jr. halted the bout at the end of the eighth round after Uchiyama unloaded with 40 unanswered punches, half of which landed, and all of which had bad intentions.

Uchiyama, 33, of Kasukabe, Japan, is rated No. 1 by THE RING at 130 pounds, having scored knockouts in six of his seven world title bouts. His lone blemish came in his previous fight, in July, when an accidental headbutt against Michael Farenas in round three rendered their bout a technical draw.

In the co-featured bout, Tokyo-native Kohei Kono (28-7, 11 KOs) struck gold in his third bid for a world title, knocking out Tepparith Kokietgym (21-3, 13 KOs), of Bangkok, in the fourth.

Kono, 32, dropped Kokietgym three times in the fourth round, prompting referee Stanley Christodoulou to stop the fight at the 2:08 mark. Kokietgym, 24, who was rated No. 2 by THE RING at junior bantamweight, loses for the first time in 18 bouts.

Also, WBC junior bantamweight titleholder Yota Sato (26-2-1, 12 KOs) of Morioka, Japan, retained his title with a unanimous-decision victory over previously unbeaten Ryo Akaho (19-1-2, 12 KOs), of Yokohoma, Japan. The scores were 117-112, 117-111 and 118-110.

Sato is rated No. 3 at 115 pounds by THE RING, while Akaho is rated No. 7.

Meanwhile, 300 miles away in Osaka, former unified strawweight titleholder Kazuto Ioka (11-0, 7 KOs) stamped himself as a force in the junior flyweight division with a dominant sixth-round knockout of Jose Alfredo Rodriguez (28-2, 17 KOs). The time of stoppage was 2:50.

Ioka, who moved up in weight after three title defenses and a stirring WBA/WBC unification victory over Akira Yaegashi in June, looked to be on his way to an early finish as he knocked Rodriguez down moments into the first round with a right uppercut, followed by a left hook to the body and a left hook to the chin. Rodriguez, who had sustained his only career defeat in his prior fight, didn’t travel all the way from Mazatlan, Mexico, to lay down, however.

Rodriguez began landing effective counters with his left hook whenever Ioka dropped his hands to work the body, particularly in round 3. Yet by the fifth, Ioka’s body work began to pay dividends as Rodriguez’s work rate dropped precipitously. Ioka’s own left hook began to land with increasing regularity, causing Rodriguez’s right eye to swell.

Rodriguez appeared to be finished by the start of the sixth round, retreating to the ropes as Ioka’s right crosses and left hooks rained in from mid-range. As Rodriguez circled back to center ring, a perfect 1-2 combination from Ioka caused Rodriguez to drop to a knee in a delayed reaction. Rodriguez rose up, but a right uppercut followed by a right cross from Ioka promptly sent Rodriguez onto his back, where he remained for several minutes.

Just before that, local favorite Ryo Miyazaki (18-0-3, 10 KOs) stepped down a division to strawweight, winning the vacant WBA strawweight title with a split-decision over former titleholder Pornsawan Porpramook (27-5-1, 17 KOs) of Sa Kaeo, Thailand. Two judges scored it 116-111 and 116-112 in Miyazaki’s favor, while the other had it 114-113 in favor of Porpramook.

Miyazaki, 24, entered Sunday’s bout as the No. 7 rated junior flyweight by THE RING, but will now be ranked at 105 pounds after picking up the belt Ioka vacated by moving up in weight. Porpramook, 34, won this very title in 2011 by defeating Muhammad Rachman, but lost it in his first defense later that year.

With a tally of 16, Japan has the most RING-rated boxers in Asia, ranking third worldwide behind United States and Mexico.

Photos / Toru Yamanaka-AFP/Gettyimages

Ryan Songalia is a member of the Boxing Writers Association of America (BWAA) and contributes to GMA News. He is also a member of The Ring ratings panel and can be reached at [email protected]. An archive of his work can be found at www.ryansongalia.com. Follow him on Twitter: @RyanSongalia.