Calderon developed a cut high atop the left side of his forehead but was unbothered by the wound. The 35-year-old southpaw connected with a right hook over the guard of Giyasov early in round three. Giyasov shook off the blow and literally ran back into position as he stood directly in front of the Miami-based welterweight.

The busiest spurt of the fight to that point saw Giyasov punch and land in combination in round four. A double jab set up a right hand, followed by a left hook which briefly caused Calderon to lose his balance. Calderon responded later in the round with a straight left hand to split Giyasov’s high but loose guard.

Concern was expressed in the corner of Calderon that he was giving away too many of the close rounds in an otherwise tightly contested affair. Calderon closed the gap in round seven and landed a right hook and left hand to the body during separate sequences. Giyasov was short with a combination at close quarters, to which Calderon responded with a left.

Calderon reverted to form in round eight where he moved around but failed to let his hands go at a point when he was seemingly well down on the cards. Giyasov landed a three-punch combination, including a pair of body shots.

Both fighters picked up the pace in round nine, largely at the urging of their respective corners. Calderon threw right hooks and straight lefts with conviction in the early portion of the frame. Giyasov shut down his attack once he reestablished his own right hand.

Calderon was forced to deal with a cut below his right eye as the bout entered the tenth round. Giyasov did his best to target the wound but didn’t cause the type of damage that would threaten a stoppage.

The bell sounded to begin round eleven, a first for both Giyasov and Calderon in their WBA-sanctioned eliminator only in the sense that the winner would advance in the welterweight rankings.

Calderon (27-1, 18KOs) had only gone ten rounds twice in his career and seemed unwilling—or unable—to make a statement in by far his most significant fight as a pro. Giyasov was content with remaining a step ahead and head to the scorecards for the third straight time as he advanced to 14-0 (9KOs) with the win.

Headlining the show, homegrown favorite Regis Prograis (28-1, 24KOs) will attempt the first defense of his WBC junior welterweight titlist Danielito Zorrilla (17-1, 13KOs).

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