Irwin, Dunlop, Hickman and McWilliams also among winners during stop-start finale
North West 200 debutant, Storm Stacey took two victories during a stop-start final day at this year's event.
The 23-year-old was declared winner of both a shortened final Superbike race and the only Superstock race of the meeting during Saturday.
Meanwhile, Peter Hickman and Jeremy McWilliams were victorious in the first and second Supertwin/Sportbike showdowns respectively whilst Glenn Irwin came out on top in the first Superbike contest of the day.
Elsewhere, 33-time TT winner, Michael Dunlop MBE was once again among the successes at the 'Triangle Circuit', sweeping to victory in the Supersport race.
Six races took place on the Triangle Circuit throughout today, starting with the opening four-lap Supertwin/Sportbike contest.
Peter Hickman swooped to victory after a late final-lap move to overcome veteran, Jeremy McWilliams who finished just over four-tenths of a second back to come home second.
Meanwhile, just over one-tenth of a second off McWilliams was Alastair Seeley who claimed the final podium place in third after holding off the late advances of winner in this class last year, Paul Jordan who recovered an overshoot at University corner on the first lap to get back into contention.
Following that was the first Superbike race over six laps, which required a restart after a short delay due to a 'minor incident' on the opening lap of the original start.
Once the six-lap contest got underway for a second time, it was a two-horse race for the lead for much of the contest between Glenn Irwin and Dean Harrison with the former working hard to snatch victory by less than two-tenths of a second from Harrison.
Meanwhile, in the battle for third, Michael Dunlop - who was as far back as sixth on lap one - battled back to take the remaining podium place at the chequered flag after getting the better of Peter Hickman and Josh Brookes in the late stages.
The following six-lap Supersport race also required a restart following an initial first-lap red flag after an incident involving Ian Hutchinson with the rider reported as being okay.
On take two, no fewer than six riders found themselves in early contention at the front of the pack - however, another red flag incident after four full laps saw the race declared early with Michael Dunlop confirmed as winner ahead of Dean Harrison in second and Josh Brookes in third.
Separately, Harrison went on to set a new Supersport lap record during the shortened race at four minutes, 31.938 seconds.
Race number four featured the only Superstock contest of the meeting which was also subject to a restart following a red flag on lap one.
Now being held over a reduced distance of four laps, the race produced a sensational result for debutant, Storm Stacey who delivered an impressive ride to take victory on his maiden appearance ahead of Michael Dunlop in second whilst Josh Brookes scooped a second podium of the day in third.
The penultimate race - the second Supertwin/Sportbike contest over four laps - saw a change in fortunes for McWilliams who - at 62 years of age - extending his own record of being the oldest rider to win at the North West 200 by taking top spot.
He finished ahead of Paul Jordan in second and Alastair Seeley in third whilst this race's winner earlier in the day, Peter Hickman, was a retirement during the showdown.
The finale to this year's event - the second Superbike race - was halted due to a red flag because of an oil spill at Juniper Hill with Storm Stacey having been leading at the time of the race being stopped.
After initially looking into plans to restart over a three-lap distance, organisers instead chose to declare the race due to the oil spill with Stacey awarded the win ahead of Dean Harrison and Glenn Irwin in second and third respectively.
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