Ozzy Osbourne was floored by his daughter’s surprise engagement at his final show … and the heavy metal legend couldn’t be happier for the soon-to-be-married couple!

Sharon Osbourne tells TMZ … she and Ozzy are over the moon about Kelly‘s engagement to Slipknot DJ/keyboardist Sid Wilson, calling it the perfect end to the perfect show. Sharon makes one thing crystal clear … she wants “a lot more babies” from Kelly and Sid, who already have a young son.

While Ozzy was surprised by the timing of the proposal, he knew it was a long time coming. Sharon tells us Sid asked the Osbournes for permission to marry their daughter a while back … and about 3-4 months ago, Sid told Sharon he was going to propose to Kelly at Ozzy’s final show, deciding to keep it as a surprise for both Ozzy and Kelly.

Sharon says she and Ozzy are planning a romantic celebration for the couple later this week. The Osbourne clan opted out of hitting the town following the proposal … the “Bark at the Moon” singer had just put in a very long day for his final concert.

As you know, Ozzy brought the house down Saturday night with a farewell performance at Villa Park in his hometown of Birmingham, England. After the show, the Osbourne family gathered backstage, where Sid dropped to one knee and popped the question in front of everyone.