The Kiwi kid who famously 'arrived' at the start of the year with his dramatic, last corner pass on Jamie Whincup in Adelaide, scored his first win since Perth in May and second for the year.
An entire engine replacement between races on Saturday followed by losing an unfixed wheel to end a horrific day was replaced with the elation of victory on Sunday.
McLaughlin aced ARMOR ALL Pole Position and finished it off with fighting victory ahead of Heavy Haulage Australia Racing's Nick Percat and Lockwood Racing's Fabian Coulthard.
It was Volvo's first win at Sydney Motorsport Park as the 21-year-old just made it home on fading tyres with Percat looming large.
"It's ridiculous," said McLaughlin of the two completely contrasting days.
"I was so thankful and relieved when I crossed the line. I'm proud of myself and the team for going with the right strategy. It was the result we had been waiting for.
"We made up from yesterday. I'm not surprised but overwhelmed we got this victory."
In the drive of his career Percat stalked McLaughlin in the closing stages. McLaughlin was nursing some tyre damage as his young rival gradually pecked back tenths of seconds lap by lap.
The South Australian 25-year-old, a Bathurst winner with Garth Tander in 2011 and a best finish of fourth in Townsville this year, scored his first podium as a single driver, reinforcing his coming of age.
He spent two seasons as a co-driver, Dunlop Series pilot and last year driving a Porsche in the Carrera Cup, honing his skills for a fulltime return to Walkinshaw Racing.
"It (Bathurst) is definitely in the past, that was 2011," he said. "Garth taught me a massive amount but I have had to change a lot with the new generation car and setting it up right for me.
"When I went off and did the Porsche thing that was the start of me as a driver and a person. I think the team can see I'm a lot different than what I was a few years ago.
"We are living the dream, all of us. We have got a great job."
The back story as always was the Championship. Mark Winterbottom struggled to finish twentieth allowing Jamie Whincup (fifth) to increase his lead to 135 points overall.
Winterbottom's weekend went from bad to worse, quickly. Another mid-pack qualifying (15) already had the former points leader battling. But a call from race control to force a drive-through penalty for a clash with his team-mate David Reynolds made it even worse.
Outside of Scott Pye in the Wilson Security Falcon and Reynolds in the Bottle-O who crashed on lap one, Winterbottom was sent back to last in the field with a big task ahead.
Officials ruled Winterbottom was to blame for the hit which made Pye and Reynolds impact, both smashing into a concrete barrier.
While McLaughlin's comeback from his shattering Saturday began with his front-row spot, no such luck for Lowndes whose Championship push also took a slight hit.
Lowndes made a mistake in the first qualifying sector, hitting a tyre bundle and damaging the front air dam and splitter. His team couldn't get him back out for the soft tyre run, pushing him from seventeenth to start last on the grid.
But as only Lowndes can do he fought from last to ninth retaining critical points on what was effectively a double points race compared to the two Saturday sprints.
The fourth contender James Courtney was also in trouble with a major transaxle failure forcing him out of the race and blowing fluid all over the track and into Whincup's windscreen.
The Championship now heads to the PIRTEK Enduro Cup, where teams will adopt co-drivers to complete the long distance races. The first of the three events is the Wilson Security Sandown 500, from September 12-14.