The New Zealanders defeated Arnold's Mariners 2-0 at Westpac Stadium and although the visitors did play some good football, is was the Phoenix's efficiency doubled with their love for playing at home that overran the Mariners in the end.
"Wellington are a very good side and they don't have a record at home like they've got for no reason, 21 unbeaten and you expect them to be one of the top teams throughout the season," Arnold said.
"Overall I thought in the first half, except for the one lapse of concentration when they did score I thought we did well, and in the second half they caught us on the break, so overall there were just two incidents that won them the game."
Arnold admitted that the state of football in New Zealand was also a major contributing factor to the Wellington club doing so well.
"Wellington and New Zealand are riding an emotional rollercoaster after the World Cup. You have 5 or 6 players out there that played out there that played at the World Cup and are extremely confident, and when you add in there (Paul) Ifill, Dylan Macallister did well against us and Andrew Durante at the back there, plus you add in a few other players, they've got a very good side," he added.