Levski had seemed certain to win a 27th league title but, in a dramatic finale, defender Dimitar Vezalov scored a bizarre own goal 16 minutes from time to shock home fans into silence as main rivals Ludogorets beat Montana to lift the trophy for a second straight year.
Slavia keeper Petkov, formerly with Levski, made an outstanding save in the last minute, depriving the home side of their first title since 2009. Vutsov, who was formerly the Levski coach, was booed.
"They received death threats via SMS after the match," Slavia president Ventseslav Stefanov said. "Now they're afraid to go back home.
"Why should I feel a traitor?" said Vutsov. "I'm a professional, I'm Slavia coach at the moment and they pay my salary."
Levski players were given a police escort as they left the stadium.
The club's chief executive Ivo Tonev said he would resign while financial director Konstantin Bazhdekov collapsed with suspected heatstroke and was rushed to hospital.
- Sports & Recreation
- Dimitar Vezalov