Marianne Marston could not disguise her disappointment after coming up short in her bid to become WBU European featherweight champion at Bethnal Green's York Hall on Saturday night.
The 40-year-old lost a split decision to Hana Horakova after the three ringside judges scored the contest 78-75, 76-77, 77-76 in favour of the fighter from the Czech Republic.
The eight-rounder was fought at a frenetic pace and Marston explained a back injury forced her to tire during the latter stage of the fight.
"I feel like I messed up tonight and that I could have done better," she told skysports.com.
"It was a tough night for me. After the fourth round I started to struggle a little bit and maybe that was my mistake.
"I've had a back problem for a few weeks and it makes it difficult to do the movement I like on my right foot.
"When it kicks in it starts to affect my legs and of course that in-turn gives you trouble with endurance."
Horakova stepped in at short notice after Marston's original opponent Galina Gumliiska failed to receive medical clearance from boxing authorities in her native Bulgaria.
That bout was supposed to be for the super-bantamweight title, but Marston revealed contesting the vacant featherweight title against Horakova was a chance she had to take.
"She (Horakova) was a heavier opponent than I was supposed to face but I really didn't want to miss this opportunity," Marston said.
"That kind of messed with things but I still feel as though it shouldn't have really affected the outcome.
"I was already supposed to have this fight back in November but the show got cancelled and I did not want to miss out again.
Asked if she expected to return to the ring for another crack at a title, Marston said: "Yes probably."
Also on the bill was 44-year-old Mark Prince - father of murdered teenager Kiyan Prince - who continued his comeback by making light work of Olegs Lopajevs, knocking the Latvian out in the first round.