The Brit was ahead on two of the scorecards by 116-112 and 116-114, while the third judge favoured the Bulgarian boxer and scored the bout 116-112.
After three straight defeats - two against Joseph Parker and one against current world heavyweight champion Oleksandr Usyk - the 38-year-old is once again back to winning ways.
What's more, the veteran also avenged his defeat to Pulev from 2016, when it was the 41-year-old who won a split decision in Hamburg.
The encounter was a gruelling one as both men went toe-to-toe and landed regularly throughout the 12-round contest.
Chisora focused on Pulev's body and continuously pummelled the Bulgarian with heavy hooks to the mid-section.
Nevertheless, the Bulgarian opponent showed incredible stamina and resilience as he not only withstood the punishment but also dished out a number of combinations.
Both men enjoyed successes, but it was Chisora who edged his rival on the scorecards.
After the fight, the Brit admitted his career is coming to an end, however he doesn't intend to go out with a couple of easy wins.
Instead, he has called out former world heavyweight champion Bronze Bomber Deontay Wilder, who hasn't fought since his second defeat to Tyson Fury last October.
He told DAZN: "I think I last won a fight three years ago. It's been a while. It was hard, Pulev is a great fighter. Very difficult and very hard.
"I'm happy today and at the same time I'm sad. I don't have many left in me, but what I have, I'm going to give it all to you guys.
"I don't have many left, so my next couple of fights… I'm on my way out. I don't want no easy fights. I want the hard fights. I told Eddie [Hearn] the other day, if he can get me the Bronze Bomber, I'd be happy. I want to fight everybody in my era. Win or lose I just want to fight."