John McGuinness finally claimed victory on Roger Winfield's Paton in the Bennetts Senior race at the Classic TT.
McGuinness had endured huge disappointment after failing to finish over the past three years, but broke his duck at last as he set new lap and race records for the class, wrapping up the win by 21.4 seconds from last year's winner Dean Harrison on the Black Eagle Racing MV Agusta.
An emotional Maria Costello rode an excellent race as she secured her maiden Classic TT podium on the Beugger Paton, finishing more than three minutes back.
Michael Dunlop on the Black Eagle MV Agusta and William Dunlop (Davies Motorsport Honda) were non-starters n the race, while Ian Lougher (John Chapman Honda) and Conor Cummins (Winfield Paton) were early retirements on the opening lap.
McGuinness held a lead of 1.5 seconds over Harrison at Glen Helen on the first lap, with Costello lying third, 6.9 seconds in arrears.
At Ramsey Hairpin, it was Harrison who moved to the front by 0.3 seconds from McGuinness with Costello remaining third, 12 seconds ahead of Alan Oversby on the Davies Motorsport Honda.
McGuinness, who led the field away at number one, was first to break the lap record as he clocked 112.043mph from a standing start, but the 44-year-old only held the mark briefly as Harrison lapped marginally faster at 112.077mph to hold a slight advantage of 0.3 seconds after the first 37.73 miles.
Costello was beginning to consolidate third, 51 seconds behind the leading pair and 14 seconds clear of Michael Rutter, who was into fourth ahead of Oversby, who was only 2.6 seconds back.
Harrison was on a charge and had extended his lead to 1.1 seconds by the time they reached Ramsey on lap two, but McGuinness smashed the lap record again, raising the bar to 113.342mph as he went straight through the Grandstand to commence his third lap, opting instead to pit for fuel at the end of lap three.
Harrison pulled into the pits for his scheduled stop at the end of the second lap, with McGuinness now credited with a lead of five seconds.
Costello was still in third place as she made her stop, although Oversby also went straight through on the Davies Motorsport Honda to move into third on corrected time at Glen Helen on lap three, with McGuinness now leading Harrison by 58 seconds on the leaderboard but with his fuel stop still to be factored into the equation.
Rutter, who had been in fourth place behind Costello, retired in the pits on the Ripley Land Seeley at the end of the second lap.
McGuinness made a smooth stop at the end of lap three and the strategy appeared to have paid off as he held sway on the Paton by 21 seconds from Harrison at Glen Helen, with Costello back up to third after Oversby stopped to take on fuel at the end of lap three.
The 23-time Isle of Man TT winner's lead was now 24.4 seconds at Ramsey Hairpin over Harrison, with McGuinness on target to finally secure his maiden Classic TT win on the Winfield Paton.
There was no late drama as McGuinness held on to take a popular win by 21.4 seconds from Harrison, with Costello an excellent third, over three minutes behind. Jamie Coward, Alan Oversby and Dominic Herbertson completed the top six.
McGuinness set a new race record for the class in 1h 21m 10.189s, bettering the previous record by a huge 57.543 seconds. His lap record of 113.342mph was also the first sub 20-minute lap on a Classic 500 machine around the Mountain Course.