The Doncaster man continued his steady rise up the rankings, controlling the fight with his sustained work-rate to take victory with scores of 117-111, 118-110 and 118-109 in Sheffield.
In the opening round, McDonnell was over eager with his attacks and Yedorov picked him off with precise jabs.
But the former British champion began to settle in the second, landing his straight right and spiteful shots to the ribs. ??
The bloodied face of Yegorov showed evidence of McDonnell???s much improved work and an uppercut ripped through the Donetsk man???s defences in the third.
A steady body attack seemed to be draining the fight from Yegorov in the fifth, but he staged a determined stand in the seventh and was punished for his bravery, with McDonnell unloading a sharp combination before the bell.
Another hurtful body shot forced Yegorov to retreat in the ninth, but he marched forward in the 10th and drove punches through McDonnell???s weary guard.
Yegorov enjoyed further success in the 11th as he landed a crisp right, prompting a final round response from McDonnell, who piled on more punches to seal a unanimous decision.
In another undercard clash, Adam Etches suffered his first professional defeat against Sergey Khomitsky.
The Belarusian added another upset win to his record, uncorking a huge right hand that sent the Sheffield man crashing to the canvas in the fourth round.
Referee Howard Foster immediately waved off the fight, with Etches laying prone on the canvas, but he thankfully recovered after a few worrying minutes.
Etches had shown flashes of the ring skills which had brought him 18 straight wins and troubled Khomitsky with clubbing hooks before the sudden, dramatic ending in the fourth.
Earlier in the night, Frankie Gavin warmed up for his home-town show with a shutout points win over Bogdan Mitic.
The 29-year-old sharpened his tools ahead of his Birmingham meeting with Chris Van Heerden on May 9, winning every round against the outclassed Mitic. ??
Displaying his neat footwork in the early rounds, Gavin moved nimbly into range to land sharp left hands on the Serb.
But the skilful southpaw seemed content to pick away at his opponent???s defences and peppered him with a precise jab.
Gradually increasing the pressure, ???Funtime??? forced Mitic onto the back foot with a crisp left hand in the seventh round.
The Belgrade man stubbornly held on until the final bell, despite spiteful combinations from Gavin, who cruised to a one-sided win.