Sandy Ryan was hit with a can of red paint en route to Madison Square Gardens, before losing her WBO welterweight world title to Mikaela Mayer.
Despite being advised by her trainer to pull out of the bout, Ryan proceeded to the venue and took the ring as scheduled.
The Briton lost a tight match on a majority decision, leaving Mayer as the world champion.
Tensions had been high prior to the fight, with Mayer accusing Ryan of poaching her long-standing coaching team, which Ryan denied.
After the fight, Ryan said: “Before coming to the venue, I had a hit and run [with paint outside the hotel]. And that was definitely set up. I’m not taking nothing away from the win, but it unsettled me.”
“Walking to the venue, I was shook up. And then it threw me off a bit of my game plan because I just wanted to fight. And you saw at the start of the fight, I was handling her quite well on the jab. I was boxing her and then I started to pick it up. But then, I was obviously pushing it too hard.”