The 57-year-old became enraged by Leeds defender Gary Kelly's late tackle on Craig Short shortly before the interval.
Kelly had already been booked moments earlier and when Warnock used a range of expletives to express his anger to Leeds counterpart Kevin Blackwell he was sent off by referee Graham Poll.
However, the Blades boss refused to go quietly and it took almost 60 seconds for a police officer to forcibly remove Warnock from the touchline and usher him into the stands.
The incident completely overshadowed an exhilarating Yorkshire derby which saw Eirik Bakke open the scoring with a spectacular own-goal after 10 minutes.
David Healy spectacularly drew Leeds level after 42 minutes before old wounds between Warnock and his former Bramall Lane assistant Blackwell reopened.
The pair fell out in bitter circumstances after Blackwell quit Bramall Lane in the summer of 2003 to become Peter Reid's assistant at Elland Road.
Warnock was upset to learn from a journalist that Blackwell was leaving and the pair's relationship subsequently deteriorated.
While there has since been a slight thaw in the cold war between the pair, it was abundantly clear there remains a significant degree of ill feeling.
This was supposed to be one of the proudest nights of Warnock's career, the Sheffield-born lifelong Blades fan who has guided the club back to the top-flight after a 12-year exile.
And with 10 minutes played the script was being played out in Warnock's favour as United forged ahead, albeit in somewhat fortuitous circumstances.
David Unsworth swung a dangerous inswinging corner over from the right flank but instead of simply nodding the ball clear at the near post, Bakke headed past Neil Sullivan.
Bakke had not found the net since scoring for Leeds in a 2-2 draw against Liverpool at Elland Road on February 29, 2004.
It was a dreadful error from the Norwegian and the lively Danny Webber threatened to make it 2-0 soon after with a curling effort which drew an alert save from Sullivan.
United's attacking triumvirate of Webber, Ade Akinbiyi and Steve Kabba continually asked questions of the Leeds rearguard.
After 25 minutes Akinbiyi fired over from the edge of the box and when he outpaced Stephen Crainey.
But Leeds were level after 42 minutes when Healy cut in from the left flank and curled a delightful left-foot effort into the bottom corner from 19 yards.
However, tensions reached boiling point shortly before the break as Warnock was banished to the stands to hint at what lies in store for the Premiership next season.
The second period failed to match the tempo of the first half but Liam Miller's stinging left-foot save drew a fine save from Paddy Kenny.
Akinbiyi also fired over when well placed but a draw, which extends Leeds' winless run to eight games, was the right outcome.