7:05 AM PT -- 9/22 -- Conor's first pitch wasn't the only botched attempt on Tuesday -- it turns out McGregor also sang a rendition of "Take Me Out To The Ballgame" during the 7th inning stretch ... and let's just say he won't be collabing with Bieber any time soon.
Of course, Conor would say he's got the voice of an angel -- after all, he applauded his bad first pitch ... admitting his accuracy was a bit off, but calling it "the most devastating first pitch you've ever seen in the iconic Wrigley Field!!"
"The venom is there, the power is there. It's a little off accurate-wise, but I'm on the one leg," Conor said. "You can see based fully on the left leg that was just recently injured. I'm happy with that."
Conor said his power was on par with the major league pitchers in the game ... and hey, we love the positivity.
Move over, 50 Cent, there's a new worst first pitch of all time ... courtesy of Conor McGregor's ceremonial toss at the Cubs game on Tuesday!!!
The sharply-dressed UFC superstar strutted to the mound for the first pitch before the Cubbies faced off against the Minnesota Twins at Wrigley Field ... and chucked his attempt about 20 feet to the right of home plate.