The 30 year-old wanted to mix it with the Mexican from the off and was obviously pushing to become the first fighter to stop Granados in 26 contests.
Several tickings off from father and trainer Kenny Porter didn’t seem to get through as the American traded leather for the duration of an entertaining scrap.
Granados took some huge punches but Porter just couldn’t end the fight early to his clear frustration.
Landing the cleaner, better work was enough for Porter to pick up the all-important rounds to see out a victory on the cards and move towards a world title shot in 2018.
Final scores were 117-111 all in favor of Porter who tired late on due to the pace of his relentless attacks.
In the aftermath, Porter revealed a hand injury that could delay a potential rematch with Keith Thurman.
Prior to the main two bouts, Sergey Lipinets overcame a cut on his forehead caused by an accidental head clash to eventually pick up Terence Crawford’s old IBF super-lightweight title.
The Russian battled through a sea of blood dripping into his eyes to take a points decision 118-110, 117-111 (twice) on the cards and claim the vacant strap.
Earlier, Dominic Breazeale claimed an eye-catching win over Eric Molina in a battle of two former world heavyweight title challengers.
Breazeale, who is on the road back from a loss to Anthony Joshua, took the fight out of Molina before putting him on the canvas prior to the contest being halted after the eighth round.
Rated highly in the WBC rankings, Breazeale has been tipped as a potential opponent for Deontay Wilder in 2018 after winning what was an eliminator for the green and gold strap.
The World Boxing Council had been quoted as stating the fight was for mandatory status, although British contender Dillian Whyte, who is chasing a bout with Wilder after winning the Silver title last week, confirmed promoter Eddie Hearn has been informed the bout was only a ranking eliminator.
Also on the bill, Commonwealth heavyweight champion Lenroy Thomas warmed up for his rematch with Dave Allen with an eight round points win over late replacement Ed Fountain.
Thomas made heavy weather of it for the duration, putting his clash with Allen in doubt, before edging a 77-74 and 76-75 (twice) decision on the cards.
The Allen fight was due to happen on the undercard of Anthony Joshua v Carlos Takam last week but was rescheduled when Thomas accepted the New York encounter.
Promoter Eddie Hearn will be happy to learn of Thomas’ victory as Allen is set to challenge for the title on the December 17 undercard of Tony Bellew v David Haye II.