Top-10 finishes ensured he secured a decent share of the points (64 then 68), before earning pole position for the final race of the weekend.
McLaughlin finished just 0.02sec faster than Australian rival Cameron Waters in qualifying, and got off to a perfect start from pole position in race three on Sunday afternoon.
The 27-year-old got off the mark quickly and put a few seconds of space between himself and the chasing pack, which is where he stayed for the entirety of the race.
Waters, coming into the race more than 350 points adrift on the season ladder in fifth place, pushed McLaughlin from start to finish though, pushing his car hard to give himself a chance of tipping up the competition leader.
In the end, McLaughlin claimed a four-second win, with Waters in second and Whincup in third.
It was a tough weekend for fellow Kiwi Shane van Gisbergen, who further lost touch with McLaughlin with just one podium finish.
Van Gisbergen was able to finish third in the second race of the weekend, but that came after a horror start to the weekend when he finished 19th after starting the opening race in third row.
In the final race, however, van Gisbergen showed more promising signs ahead of next weekend's event at the same venue, qualifying in 13th but improving to an eighth-place finish.
Supercars Championship standings:
1. Scott McLaughlin 1556 points
2. Jamie Whincup 1433
3. Chaz Mostert 1172
4. Shane van Gisbergen 1157
5. Cameron Waters 1157
6. Nick Percat 1069
7. David Reynolds 1046
8. Mark Winterbottom 1024
9. Fabian Coulthard 1018
10. Lee Holdsworth 993