Traditionally the opening line is:
There's on-ly onnnnnneeee [insert name here] with [insert name here] being 4 syllables, like "Vinnie Lia", for example.
So, from the above...
"We love Wellllllllllll - ing-ton Phoenix" would arguably work.
Or,
"We love ouuuuuuurrrrrrrrr Welly Phoenix" would work too.
Personally, I am not a big fan of either of these as a first line. I think the chant is so universally well known it has to start with "There's only one...."