[4] Taylor captured his unified titles in 2019 as part of the World Boxing Super Series tournament, defeating IBF champion Ivan Baranchyk via unanimous decision (UD) in May[5] and WBA (Super) champion Regis Prograis via MD in October, winning the vacant Ring title in the process.

[6] After nearly a year out of the ring, Taylor successfully retained his titles against the IBF's mandatory challenger, Apinun Khongsong of Thailand, via first-round knockout (KO) in September 2020, leaving Ramírez' mandatory defence against Catterall as the final obstacle to an undisputed fight.

In the sixth, a round which saw Taylor suffer a small cut to the corner of his left eye, the Scotsman landed a short left-hand counter on Ramírez' jaw, knocking the American to the canvas.

All three judges scored the bout in favour of Taylor with 114–112, giving the Scotsman a unanimous decision victory to become Scotland's second ever undisputed champion after Ken Buchanan, the first Brit to be undisputed since Lennox Lewis in 2000 and only the third man to do so since the four belt era began in 2007 after Terence Crawford and Oleksandr Usyk (Bernard Hopkins and Jermain Taylor had been four belt champions before the WBO became recognised as a major title).

[11] Speaking after the bout BBC Radio 5 Live boxing pundit Steve Bunce said "It was a great fight.