Northern Irishman Frampton added Bury-born Quigg’s WBA title to his own IBF belt having got the nod courtesy of 116-112 counts in his favour by two judges, with the other giving the bout to his opponent 115-113.
Frampton had looked well in control for much of a contest that was failing to live up to the hype that had preceded it, until Quigg started making more of an impression as it developed into a decent battle in the final few rounds.
Frampton told BBC Radio 5 Live afterwards: “I did what I had to do to make it easy for myself.
“I couldn’t believe what was going on when I heard the split decision – I felt I was a comfortable winner – but it’s onwards and upwards for me now.
“I knew it was going to be a tactical fight all along and a bit timid but you have to do what it takes to win.
“I’m not going to rush into silly punches. You have to be smart. I was and I got the win.”
The much-anticipated bout in front of a cacophonous 20,000 sell-out crowd marked the climax of a rivalry which had been brewing for several years between two fighters who both went into it with undefeated records.
And Frampton, 29, added: “I’m proud to have beaten a very good fighter. There’s a lot of history between our teams but he was a worthy champion.”