The Rotherham-born yachtsman, a long time United supporter, set off on a lap of honour at half-time and received a standing ovation but he was then forced to watch his side settle for a point.
United carved out a couple of chances early on, midfielder Greg Halford trying his luck with a low drive, the ball flying inches wide of the far post before the lively Billy Sharp set up out an opportunity for Darius Henderson.
Sharp teased centre-back Roger Johnson, a £4million target for Hull City and West Brom, before picking out former Watford striker Henderson, who squandered the chance heading wide from eight yards.
Cardiff then caught the Blades on the break. Ugo Ehiogu was slow to react as Ross McCormack burst into the area but the lanky Matt Kilgallon stuck out a foot to clear.
The Welsh side almost found a way through when Peter Whittingham passed inside to McCormack whose low left foot strike had pace but was hit straight at Paddy Kenny who was guarding his line.
Former Wales international Gary Speed ballooned a shot high over the bar as united looked for a way through.
James Beattie, playing his first game of the season after undergoing knee surgery, replaced Sharp in the 80th minute and Danny Webber came on for the ineffective Michael Tonge in stoppage-time but Cardiff were unable to hang on in a nail-biting finish.