ALLENTOWN, Pennsylvania – Guillermo Rigondeaux kept his promise to trainer Ronnie Shields on Saturday night.

Seven months after engaging in what Shields considered an unnecessary slugfest against Julio Ceja, Rigondeaux returned to his defensive, tactical ways Saturday night. The former 122-pound champion definitely didn’t excite the crowd at PPL Center or those watching on Showtime, but he beat Liborio Solis and won a world title in a second weight class.

The 39-year-old southpaw was conservative, yet effective in the rare instances when he let his hands go. The Cuban-born Rigondeaux (20-1, 13 KOs, 1 NC) knocked down Solis in the seventh round, hurt him again in the 10th and won a 12-round split decision to capture the vacant WBA world bantamweight championship.

Judges Ron McNair (116-111) and Kevin Morgan (115-112) scored Rigondeaux the winner in his debut within the 118-pound division. Judge Don Ackerman scored the fight 115-112 for Panama’s Solis (30-6-1, 14 KOs, 1 NC), who often was the aggressor, but didn’t land many punches.

His victory Saturday theoretically moved Rigondeaux toward a fight against unbeaten Japanese star Naoya Inoue. The hard-hitting Inoue (19-0, 16 KOs) owns the WBA’s “super” championship in the 118-pound division, but the WBA typically doesn’t force its “super” champions to face its “world” champions.

Inoue, also the IBF’s 118-pound champion, is scheduled to face the Philippines’ Johnriel Casimero (29-4, 20 KOs) in a bantamweight championship unification fight April 25 at Mandalay Bay Events Center in Las Vegas. Casimero holds the WBO 118-pound crown.

Though unusually dull, this fight was far less difficult for Rigondeaux than his previous bout.

The typically tactical Rigondeaux traded punches with Ceja for much of their fan-friendly slugfest and trailed on all three scorecards through seven rounds. Rigondeaux dropped Ceja with a left hand late in the eighth round and stopped the Mexican veteran with second to go in that eighth round June 23 bout at Mandalay Bay Events Center in Las Vegas.

Before Rigondeaux defeated him, Solis had won five consecutive fights, all against pedestrian opposition.

After hurting Solis for the second time in the bout during the 10th round, Rigondeaux boxed and moved during the 11th and 12th rounds. Neither fighter landed many punches in those dull six minutes.

Rigondeaux rocked Solis with a straight left hand at 1:24 of the 10th round. Solis stumbled backward, but stayed on his feet and finished the round without getting hurt again.

Rigondeaux scored a knockdown during the seventh round, but he resumed his cautious strategy throughout an uneventful eighth round.

Rigondeaux barely threw any punches in the previous five rounds, but he staggered Solis with a quick, short left uppercut that knocked Solis into the ropes with 2:23 to go in the seventh round.

Esteves counted it as a knockdown because the ropes held up Solis. Before Esteves could separate them and begin counting, though, Rigondeaux drilled Solis with another straight left hand and threw several more punches toward him.

Solis, frustrated by Rigondeaux’s unwillingness to engage, implored Rigondeaux at the end of the sixth round to stand and fight.

Unfortunately, the forgettable fourth and fifth rounds mirrored the dull third and second rounds. Rigondeaux moved around the ring in those rounds, Solis unsuccessfully attempted to hit a moving target.

Fans grew very restless during the third round, the second straight boring three-minute period. Rigondeaux easily slipped Solis’ punches in the third round, but he barely attempted to land punches.

The second round completely lacked action. Rigondeaux feinted for much of those three minutes and rarely engaged.

Rigondeaux drilled Solis with a back-to-back, straight left hands about 1:20 into the fight. Solis drilled Rigondeaux with a right hand that knocked him off balance just before the first round ended.

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