The Silent Roller, 31, overpowered the ex-IBF title holder, 39, with two knockdowns before a sustained assault forced the referee to intervene in the fourth round of their bout on Sunday (15.02.26) night.
Ajagba (21-1-1, 15 KOs) came into the bout having added significant muscle during camp and started positively, edging a competitive opening round with heavy right hands.
Martin (29-5-1) responded well in the second, using his speed and experience to land sharp left hands while circling away from danger.
For a time, Ajagba struggled to cut off the ring and relied too heavily on loading up with his right, but the contest turned dramatically late in the third round.
With Martin sliding along the ropes, Ajagba set his feet and fired a straight right hand down the middle that sent Prince crashing to the canvas.
Although Martin beat the count, his balance looked compromised as Ajagba pressed forward with renewed authority.
The finish came early in the fourth, as a short right hand dropped Martin for a second time and this time Ajagba remained composed, stepping in behind his lead shoulder and letting his combinations go in tight, controlled bursts.
As Martin sagged against the ropes under a series of clean shots, referee Thomas Taylor waved the fight off at 1:11 of the round.
Speaking after the fight, Ajagba said: “I’m ready to fight anyone in the division.
“I’m ranked in the top 10, but no one is saying my name. I’m putting the heavyweight division on notice.”
The victory marks an important rebound for Ajagba following a frustrating draw with Martin Bakole, a bout many observers felt he had done enough to win.
Here, he showed improved patience once he had his opponent hurt, resisting the urge to rush his work and instead picking his shots carefully to secure the stoppage.
For Martin, it was a fourth defeat in his last eight fights and another setback in his attempts to reinsert himself into the title picture.