The Formula One arguments and protests spilled over into 1981 in a dramatic six-lap race.
Graeme Crosby could not set off at his allocated time because of chain problems on his big Suzuki. He was allowed to start at the rear of the field, but with no time allowance.
Joey Dunlop was the early leader on a Honda, but, after being forced to change a tyre at his pit stop, he was relegated to second by Ron Haslam, who went on to win from the Ulsterman. Crosby was in brilliant form and fought his way back to third from the back of the field. However, Suzuki protested - after Haslam had been garlanded the winner - that Crosby should have been given a time allowance.
Two hours later Crosby was declared the winner and Honda were furious - so furious that they dressed their riders in all-black leathers and painted their machines black for the Classic at the end of the week.
It was a protest that badly misfired.
Crosby was never headed. Dunlop's increasing Honda challenge ended when the Ulsterman ran out of fuel on the third lap, having just raised his absolute lap record to 115.40mph. Crosby thus completed an easy double, with teammate Mick Grant and Alex George on the only all-black Honda to finish.
Bad weather once again played havoc with the Senior and also produced a cruel twist of fate for the luckless Chris Guy. After the start had been postponed for one hour, he led the field, but after two laps the race was stopped because of worsening conditions. A day later Mick Grant, riding a Suzuki, was unchallenged in a race that ended in heavy rain. Crosby went out on the first lap and poor Guy crashed at Braddan. Donny Robinson took full advantage of the conditions to finish second in front of impressive TT newcomer John Newbold.
Steve Tonkin broke the Yamaha domination in the six-lap Junior 250, riding Ruth Randle's Armstrong. Graeme McGregor, on a Kawasaki, was his main challenger and led Tonkin by 0.2 of a second going into the last lap. The unfortunate Australian hit mechanical problems, leaving Tonkin a popular winner from the Yamahas of TT debutant Bob Jackson and the experienced Charlie Williams.
Tony Rutter dominated the Formula Two race on his Ducati, setting a new lap record, while in the Formula Three class Barry Smith completed a hat trick of victories on his Yamaha.
World Champions Jock Taylor and Benga Johansson produced two superb sidecar victories on their 750cc Yamaha-powered outfit. In the first race they hammered the lap record with a speed of 108.12mph to win from Mick Boddice and Derek Bailey. In the second, held on damp roads, they coasted home in front of Dick Greasley and Roy Hanks.