However, unlike Reid, McIntyre managed to nurse the car home in eighth holding off a valiant charge from Paul Manuell.
Reid, whose team worked frantically to get the car back on the grid, finished fourth behind Greg Murphy, Booth and McLaughlin.
By fending off Manuell, McIntyre clinched the first of three titles making up the V8 SuperTourer series - sprint, endurance and overall championship - by just two points from Reid with Murphy in third.
"During the break [between race two and three] we'd tried to make the car a bit quicker again but I think we went in the wrong direction," McIntyre said.
"By around the tenth lap the gearbox started playing up - it was miss-shifting. I'd change gear but it would go back to the previous gear.
"Others just kept going past me and there was nothing I could do. I was down in ninth and saw Reid had got in front of Heimgartner, so knew I had to do more. I only just managed to get past Paul Manuell and managed to keep him behind me as the gearbox was miss-shifting really badly on the final lap.
"It came down to just two-tenths of a second at the end to hold eighth place and take the title. I managed to get what I needed out of the car, but man, it was close."
McLaughlin came back with vengeance to take pole and all three races over the weekend to put the disappointment of Manfeild behind him, where his team had to withdraw because of mechanical issues.
Podium in Portugal
Kiwi open wheel racer Chris van der Drift made up for his eight place in race one at the weekend in the Auto GP Series at Portimao, Portugal by grabbing a podium in race two.
He started on pole for race two but couldn't hold of the fast charging race one winner Adrian Quaife-Hobbs.
He gambled starting on soft tyres and the plan looked good, until safety cars ruined the teams race strategy but the New Zealander held of Sergey Sirotkin who filled out the podium.
As a result of his strong finish in race two van der Drift remains in fourth place in the championship behind Sirotkin, Pal Varhaug and Quaife-Hobbs.
The series heads to the penultimate round in late July at Curitiba, Brazil.
Richie's Belgium battle
Richie Stanaway has been hospitalised in Paris after suffering broken vertebrae in the Renault 3.5 litre championship.
Despite being quickest in Friday's practice, Stanaway crashed in qualifying and had to start from the rear of the grid. Air pressure failure meant he had to return to the pits after the warm up lap. Race two proved no better when Stanaway (20) ran up the back of Carlos Huertas in heavy rain getting airborne before smacking back into the track.
The race was red flagged when it was obvious Stanaway was having difficulty getting out of his car.
