The metal star has been a gossip column fixture in recent weeks after admitting he is once again battling his addictions following an alcohol and drug relapse 18 months ago.
The 64 year old has also been dogged by persistent speculation that his marriage to Sharon Osbourne is on the rocks, but he ignored the rumours to take the stage with his reunited bandmates at Auckland's Vector Arena.
Osbourne, who was not wearing his wedding ring, joined bassist Geezer Butler and guitarist Tony Iommi for a two-hour set which included their songs Fairies Wear Boots, Snowblind, N.I.B. and Children of the Grave.
The heavy rockers are scheduled to play concerts in Australia and Japan this month (Apr13), followed by a tour of Europe which begins in Finland on 20 November (13) and culminates with a hometown gig in Birmingham, England on 20 December (13).