"It's been a long two years to be able to think of that kind of stuff," said Luke. "I'm just happy to keep building off the back of that trial and hopefully I can keep going."
The Warriors' discipline let them down with a 7-1 penalty count in the first half, but their defence did well to contain the bigger Souths forwards and force the opposition to score all their tries out wide.
"That's probably been rare in the last couple of years," he said. "When teams have done that [dominated possession and territory], we haven't been able to defend them, so it was good to turn them away a lot of times. They got a couple of tries but the best thing about that was they had to go around us to score, they didn't come through us. The boys really did well."
The side will draw confidence from the result, having claimed a rare win across the Tasman and their first in 10 visits to Perth, while also halting the nine-game losing run that ended last season.
However, Luke warned the victory would be hollow if they don't defeat the Titans at Mt Smart on Saturday and start their season with consecutive wins for the first time since 2009.
"This game isn't going to mean anything if we can't back it up. We can have a little celebration and be happy about it but we've got a tough task to back up against the Titans and it'll be game-on again. We haven't had a good run playing over in Australia, so it's good to tick this one off."
Second rower Tohu Harris performed well in his club debut but had concerns over his new side's poor discipline.
The former Melbourne Storm forward and other senior players kept reminding the team to stay on-task as they repelled wave after wave of Rabbitohs attacks.
"It was a great experience and we got up in the end," Harris said. "There's definitely a lot for us to work on, especially that last 25 minutes.
"[The message was] just to focus on our next job. We can't control what's happened or what the ref has called, we've just got to react and respond and think about what we've got to do next.
"For the most part, we did a good job at that, but our discipline can be better. Especially towards the end of sets, we did give away a few penalties that probably could be avoided.
"We went away from what got us in that position, but it's a good start to the year and hopefully we can build off the back of that."