McLaughlin scored Volvo's first Australia Championship win in 28 years while Holden's Lowndes grabbed win number 15 in Perth – the most ever – with Ford's Mark Winterbottom consolidating his Championship lead.
Reigning Champion Jamie Whincup had a topsy turvy day with a seventeenth and a second but still managed to step up a place to fifth on the Championship ladder.
Lowndes and Whincup but alluded to the Champion Red Bull Racing Australia team still trying to find their best. Lowndes struggled with his car in the opening assault but not as badly as Whincup before both charged back in race two.
"We had a mixed day. We had a string car at the start of the first race but chewed the tires pretty quickly. We changed all four tires and when back out but in all the traffic you suffer," Lowndes said.
"We sat down and really thought about what we wanted. We need longevity, we needed longer life in the tires. We softened the car right off and it proved the right decision.
"We are still working very hard to get the performance. It's not coming easy and today was an example of the team getting it right."
An upbeat Whincup spoke like it was almost his first career podium. The spark appeared to be back in the five-time Champion after two disastrous events, notwithstanding his first race today.
"I thought we (turned the corner) a few rounds ago but it all went to shizzle again. I won't make that statement again. We are happy with today's result but we are not out of the woods yet," he said.
"It was definitely a good race for us. We put the front wheels on the back and the back wheels on the front. I didn't think I would be on a podium today that's for sure."
McLaughlin got jumped in the opening race leaving Lowndes to shoot away but an incredibly strong car and good tire conversation the young Kiwi took his time, waiting for an opportunity to get by Lowndes in the pits and claim his first Volvo race win.
"I'm very stoked to have it (a first Championship win) happen. I felt the pressure there but now we have done it. It's something we can all be very proud of," McLaughlin said.
"I just rate racing up the front. Everybody gives enough respect. We can get through areas side by side without any trouble. Its good racing and sometimes they are not dickheads you could say. It's just good racing, I enjoy it."
The youngster didn't have such luck in the second race when he lost track position in the stops. The opening 42 laps was a replica of the first as Lowndes assumed the early lead from McLaughlin. It stayed that way until most of the field pitted for fresh tires.
McLaughlin was jumped by Winterbottom and Whincup in pit lane. There was no evident problem with the stop which left him in fourth as his car did not appear to be the weapon it was in race one. That was where he finished.
"I obviously stuffed the start up (in race two). We probably didn't capitalize on the conditions in the second race there," he said.
Russell Ingall started third on each grid and despite great jumps on both occasions found himself in poor position. In race one his tire life on the rough surface cost him dearly, something the team focused on in the second of the Super Sprint legs.
Unfortunately for the veteran he again faded in the second race.
Whincup also struggled badly in the first race before coming back in the second. He lost another wad of points from race one falling almost 200 points behind Championship leader Winterbottom.
Both Erebus Motorsport V8 Mercedes-Benz cars mixed it at the front in the first race, maintaining top five positions through the early period. An early pit stop by Davison hurt him towards the end of the race as he finished seventh while Lee Holdsworth went with the others and held on for fifth.
Fabian Coulthard got points back on Lowndes in the first feature with his second place ahead of Lowndes in sixth while Winterbottom also clawed a few points further in front with his fourth.
Both races were all about tires, with most of the field pitting for fresh rubber. Shane van Gisbergen and Jack Perkins stayed out in the first race, but the gamble didn't pay off, particularly for the TEKNO driver who finished last.
And while it looked as if Winterbottom would take third, teammate Chaz Mostert jumped him for the podium, his second consecutive after finishing third in the final race in New Zealand.
Holdsworth finished fifth in race one with Lowndes, Will Davison, Todd Kelly, James Courtney and David Reynolds completing the top 10 in the first race.
Coulthard – who briefly held second in the Championship after the day's first race – finished fifth in race two with Chaz Mostert, Scott Pye, Courtney, Reynolds and Ingall completing the top 10.