Sharp entered the title-deciding weekend just one point ahead of Hitech racer Macintyre, but a lights-to-flag win from pole in the opener, with Macintyre third, put the New Zealander in a good position to take the spoils.
Both drivers safely navigated starting at the back of the reversed-grid middle race but Macintyre only slightly reduced Sharp's lead by finishing seventh to his rival's 11th.
Although Sharp was beaten off the line in the third and final contest by Deagen Fairclough, he maintained the runner-up spot throughout the race and remained around a second ahead of Macintyre to claim the glory by an eventual margin of 13 points.
“It means everything – all the hard work and sacrifice has definitely paid off,” a delighted Sharp told Autosport.
“It’s been a year of ups and downs and some of the highs have been very high and the lows very low, but massive thanks to the team - I still can’t believe it’s happened!”
Sharp says he's “not 100% sure” which series he will progress to next year and will now assess different options.
“I’ve got a great relationship with Rodin Carlin - we’ll see what happens,” he added.
Macintyre, meanwhile, admitted “there wasn’t a lot I could’ve done in that race” to deny Sharp the title but the 2022 Ginetta Junior runner-up was still happy to push his more experienced rival so close.
Sophomore driver Sharp grabbed the early advantage in the title battle after a strong opening meeting of the season at Donington Park, in which he took a remarkable victory having started 20th in the reversed-grid race.
But it was not until event seven at Croft in July that Sharp triumphed again, and that victory drought enabled Macintyre to close in and then usurp the New Zealander at the top of the standings.
Yet Sharp proved resurgent after the summer break, scoring six podiums in 10 races to regain the initiative - aided by Macintyre spinning out of qualifying at the series' second visit to Donington Park and putting him on the back foot for the rest of the weekend.
That all meant the pair arrived at Brands Hatch separated by just a point to set up the intriguing finale.
Among the other British Touring Car support categories, it was anything but evenly matched in the Porsche Carrera Cup GB as Team Parker Racing's Adam Smalley had already sealed the title last time out at Silverstone after a dominant display.
But other champions were decided at Brands with second place in the Mini Challenge opener enough for Excelr8 Motorsport driver Dan Zelos to regain the crown, adding to his 2021 triumph - which came in much closer circumstances.
Then Joe Warhurst - who is in the running to be the new Porsche GB Junior - landed the Porsche Sprint Challenge GB title in the second of three races having taken five wins in a row to usurp long-time table-topper Steve Roberts to make it a very successful Porsche racing season for Team Parker.
