Scotland's Lee McGregor was stopped by Michael Gomez Jr after six rounds of a controversial lightweight bout in Doncaster.
Manchester's Gomez Jr had motioned to head butt his 29-year-old opponent in the ring before the start of the contest.
McGregor, who had been looking to rebuild his career a year after his devastating knockout defeat by countryman Nathaniel Collins.
He had also hoped for a day of double celebration as his beloved Heart of Midlothian went toe-to-toe with Celtic for the Scottish Premiership title.
However, hours after Celtic retained their title with a 3-1 win, Gomez Jr ended McGregor's hopes with a flurry of punches midway through the scheduled 12 rounds.
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