The Mariners were thoroughly outplayed by a resurgent Glory outfit at nib Stadium in stifling conditions and it was a miracle they were still in with a chance of leveling late in the game.
Unfortunately for Perth, the equalizer did come with three minutes remaining in regular time to force a 1-1 draw and Arnold admits that his side achieved the point with an element of luck.
"Overall Glory were probably the better side tonight but we will take a point," said Arnold.
"You have to give full credit to the Glory tonight, they had the bye last week, Fergie (Perth Coach Ian Ferguson) has obviously freshened them up and they came out with the intention of showing us that they are much better than what they were when we played them in Sydney."
The Mariners' goal came about after Arnold did some tinkering from the bench, bringing on striker Daniel McBreen for Adam Kwasnik, and it paid off as the former Glory man had a hand in the 87th minute Patrick Zwaanswijk header.
"I tried to change things for us because it wasn't working for us. A couple of players were struggling with the heat. To put big Danny up front, he's a hero over here and has a great reputation and I wanted a reaction from him and in the end he did well for us after great action from Michael McGlinchey," said Arnold.