Rahmonov got the better of the early exchanges by showing some fast hands to counter the oncoming attacks. However, the Cuban came on strong as the round drew to a close.
Iglesias picked up where he left off in the second stanza, bombing forward and throwing some big shots at the Uzbek.
The Cuban pummelled his opponent throughout the second and turned the scores around to six points in his favour.
Rahmonov began the third round brightly but Iglesias rose to the challenge and wrapped up a 21-15 victory.