Maccarinelli has won 29 of his 33 pro fights
Enzo Maccarinelli suffered a third-round stoppage in Manchester to raise the prospect of retirement for the former WBO cruiserweight champion.
The 28-year-old from Swansea was battered from the off by unbeaten Russian Denis Lebedev.
And the referee called a halt after an uppercut and a barrage of lefts and rights left the Welshman reeling.
"It looks like it [retirement], I'm just devastated," said Maccarinelli. "I don't think I've got it any more."
Since his emphatic defeat to David Haye in a title unification match last year, Maccarinelli overcame Mathew Ellis in two rounds before slumping to a surprise ninth-round knockout against Ola Afolabi in March.
Before the fight against Lebedev, Maccarinelli had conceded that his meeting with the Moscow fighter, also promoted by Frank Warren, could represent a "last-chance saloon".
But as early as the second round Maccarinelli was relying on single shots, while Lebedev, who is now unbeaten in 18 fights, with 13 knockouts, was never troubled.
A clean uppercut through the guard wobbled Maccarinelli in round three, before Lebedev pounced on him and pinned him on the ropes with left and right hooks.
One right in particular had the former WBO champion reeling before a merciful Terry O'Connor stepped in to end the contest.