Results from Wembley Stadium, London, UK:
Ex-world champion Scott Quigg began life under Freddie Roach with a points victory over Viorel Simion.
The featherweight won the IBF title eliminator through a unanimous decision with judges scoring the contest 117-111, 117-111 and 115-113.
It was far from the complete performance from the 28-year-old as he took punishment during the fight, offering an open defence at times during the fight.
The man from Bury is now targeting a summer showdown with Welshmen Lee Selby for the IBF title.
Luke Campbell made it two wins out of two at Wembley as he overcame a slow start to defeat Darleys Perez.
Perez was deemed unfit to continue following an arm injury and retired from the fight in round number nine.
The Columbian started the quicker out of the two, beating Campbell to the first exchanges. However, Campbell’s class came through as momentum shifted with the 29-year-old dominating with the jab.
The Olympian extends his record to 17-1 and is now in line to face a ringside Jorge Linares for the WBA crown.
Olympic gold medallist Katie Taylor captured the WBA International lightweight crown as she saw off a stubborn Nina Meinke.
Taylor, also a five-time world amateur champion, extended her undefeated record to five after Howard Foster intervened in the seventh round.
The German was deemed unable to continue the fight having received severe damage to her right cheekbone and sustained punishment throughout.
Earlier, Joe Cordina kicked off the Wembley undercard and carried on from where he left off last week with a first-round knock-out of Sergej Vib. The Welshmen produced a stunning set of explosive combinations to knock the Russian down twice before the fight was halted.
12 – IBF/vacant IBO/WBA Heavyweight titles
Anthony Joshua 18-0 v
Wladimir Klitschko 64-4
12 – WBA Featherweight title eliminator
Scott Quigg 32-1-2 v
Viorel Simion 21-1
4 – Cruiserweight
Lawrence Okolie 2-0 v
Russ Henshaw 7-4
4 – Welterweight
Josh Kelly 1-0 v
Faheem Khan 9-10-2