Frank Sanchez had to go deeper than ever before as a pro, all for a fight he accepted on very short notice.

In the end, it was another win for the unbeaten Cuban heavyweight who turned away the challenge of Belgium-based Jack Mulowayi over 10 rounds Saturday evening at Santander Arena in Reading, Pennsylvania.

Scores were 100-90 across the board in favor of Sanchez, who came in as a replacement for injured Efe Ajagbe.

Action was brisk in the early rounds, though remaining in one direction as Sanchez looked for the latest in a career of early knockouts. The Las Vegas-based Cuban boxer scored with right hands and had Mulowayi fighting on the defensive, an unfortunate trend that would carry throughout the Showtime-televised opener.

The closest either came to having the fight stopped occurred in round four, when a clash of heads left Mulowayi momentarily dazed. Both heavyweights moved past the sequence, though action never really picked up from there.

Mulowayi—a Congo-born boxer now based out of Belgium—had his singular moments late in the fight, but nothing to make his United States debut a memorable one. Efforts to come forward caused Sanchez to readjust in round seven, the first time in his pro career any of his bouts have reached that point. The unbeaten heavyweight quickly adapted, regaining his composure and scoring with thudding—if singular—right hand shots which froze Mulowayi in his tracks.

Mulowayi suffers his second career loss, both coming within his last three starts. The Congolese heavyweight falls to 7-2-1 (3KOs).

Sanchez remains unbeaten, improving to 14-0 (11KOs) with the win. The bout marked the second straight time he made his way to the televised portion of the show thanks to injuries shaking up the original limit. Prior to replacing Ajagbe, the slot was originally reserved for a bantamweight bout between former titlists Rau’Shee Warren and Emmanuel Rodriguez.

An injury suffered by Warren changed those plans, ultimately paving the way for Sanchez to pick up his third win in a span of less than four months.

The bout opened a live Showtime-aired tripleheader, topped by a 10-round junior middleweight bout between former title challenger Erickson Lubin (21-1, 16KOs) and Nathaniel Gallimore (21-3-1, 17KOs). Also on the show, former lightweight titlist Robert Easter Jr. (21-1-1, 14KOs) debuts at junior welterweight versus veteran contender Adrian Granados (20-7-2, 14KOs).

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox