The podium finish comes after he was narrowly pipped to third place by Scott McLaughlin at the Truck Assist Sydney SuperSprint.
For Courtney, the podium finish at Hidden Valley Raceway brought mixed emotions after a documented turbulent period.
Following a 10-year spell at Walkinshaw Andretti United, Courtney departed to join Team Sydney at the beginning of 2020.
That was short-lived after the two parties split. Courtney was soon left on the sidelines and seemingly without a way back into the sport.
As a result of the coronavirus pandemic, 23 Red Racing sponsor Milwaukee terminated its contract early, which resulted in Will Davison being left without a drive.
Backed by Boost Mobile, Courtney made a swift return to Supercars in place of the ill-fated Davison.
“It's been pretty full-on for a lot of reasons,” said Courtney.
“I'm not going to lie, I got a bit emotional. I thought I was going to be on the podium last round but Scotty got me on the line.
“It was good racing with Anton, I pushed him quite hard the whole way especially after the Safety Car and congratulations to him, the first win of many I bet.
“It's been well written about, what's been going on and I think I got a little bit emotional because I was looking at Riana (Crehan) and I know the emotion that her and Will and what's going on because I've been on that side of the fence.
“It all just came out. I probably didn't make a lot of sense. I feel for them and their position but equally I'm very happy with the result for Boost Mobile and all the guys.
“They've put a lot of faith in me and trust and also into Tickford. There's been a lot going on and it was good to have that release.
“I'm the exact opposite to Anton. I'm the guy that's going crazy and crying and all sorts of stuff. I can't hide my emotions and we'll celebrate this one pretty hard.”
Courtney said he nearly made a lunge for the lead on the final restart of the race.
However, a pass wasn't forthcoming and Courtney ultimately held station to secure second place.
“On the restart, when Whincup was pushing me, I was actually catching Anton quite a bit,” said Courtney.
“But it's hard to follow him with the way the cars are getting now and the heat coming off the car in front.
“Unless Anton made a mistake, it was going to be hard to get past him with the calibre of driver he is
“He kept his nose clean, unfortunately for me but good for him. It probably didn't look that exciting but both of us were battling pretty hard at the end there.
“My fastest lap of the race was the second-last one trying to pass Anton.”
Supercars is back on-track today at 11:40 local time/12:10 AEST for a pair of qualifying sessions ahead of Races 14 and 15 of the Virgin Australia Supercars Championship.