SINGAPORE, Singapore (AFP) — American MMA fighter Holly Holm backed Conor McGregor to cause Floyd Mayweather problems on Thursday after their cross-over boxing showdown was confirmed. Ireland’s McGregor will be the heavy underdog against 49-0 Mayweather but Holm knows a few things about upsets, after she ended Ronda Rousey’s unbeaten run with a brutal knockout in 2015. “I’m one of those who believes in being able to cross over,” said Holm, a former boxing world […]