Jack Osbourne marks 10 years sober amid dad Ozzy's ongoing struggles

Reality TV star Jack Osbourne is celebrating 10 years sober, just days after his rocker father Ozzy confessed to relapsing in his battle against drink and drugs.

The 27 year old endured a struggle with substance abuse in his youth, but managed to overcome his demons in 2003 after admitting himself into a psychiatric ward and a rehab center, and he reached the major milestone on Sunday (21Apr13).

Marking the personal triumph on Twitter.com, he wrote, "Well I never thought this was gonna happen 10 years ago".

The new dad then shared a screenshot of an iPhone app, titled Twelve Steps The Companion, which recorded that he had been sober for an impressive 3,654 days.

However, Jack's celebrations are sure to have been overshadowed by his dad's relapse - Ozzy Osbourne came clean about his renewed battle for sobriety last Tuesday (16Apr13), revealing he fell off the wagon 18 months ago, but had been back on track for 44 days.

The admission came shortly before he set off on a world tour with his reunited band Black Sabbath. They played their first show of the trek in Auckland, New Zealand on Saturday (20Apr13) without incident.