"This was my last match with Piroozi,” said the Portuguese coach after last year’s beaten semi-finalists advanced courtesy of Rivaldo’s hotly disputed first-half penalty.
“I wrote a letter giving notice of my resignation two days ago but Piroozi will always be in my heart and I wish them success for the future.
"If you're looking for someone to blame (for the elimination) then blame me but my conscience is clear that I've done my best for Piroozi," Vingada continued.
Rivaldo scored the only goal of the game from the penalty spot in the 41st when, after going to ground under pressure from Piroozi defender Nabiollah Bagheriha, the Brazilian picked himself up to fire the visitors ahead.
And Group B winners Piroozi failed to find a way past a well-organised Bunyodkor defence in the second-half as the Uzbek double winners advanced to the quarter-finals as calls for Vingada and the club's directors to resign echoed around the Azadi Stadium.
Vingada said he was unhappy with the decision of Kim Dong-jin to award the first-half penalty suggesting that Korean referee may have been swayed by Rivaldo’s reputation.
"In my opinion the referee controlled the match because he gave the penalty,” stated the former Jordan national team coach.
"If anyone else had thrown themselves on the floor other than Rivaldo he wouldn't have given the penalty but because it was Rivaldo he gave it."
Bunyodkor coach Amet Memet, however, quickly defended the Brazilian former World Player of the Year.
"The bench was far away from the incident and I didn't see it very well but I can tell you that Rivaldo didn't dive,” said Memet.
"In my opinion what's important is the performance of the players and coaches not the referee and I think the performance of our staff was much better than the referee’s."
Group D runners-up Bunyodkor, who currently lead the Uzbek League with a 100% record after 10 games, advanced to the quarter-finals of the AFC Champions League for the second consecutive year and ended Iranian hopes in the competition.
"I'm 100% pleased with my players because we won but I have to say that it wasn't a very interesting match and we've played much better,” added Memet.
"But in the end we won away from home and have reached the next round and this is a great thing."