After Louis D'Arrigo cancelled out Trent Ostler's opener on the stroke of halftime at Melbourne's AAMI Park, Mata somehow dropped a deep corner on to an unmarked Nishan Velupillay for the go-ahead volley in the 53rd minute, before setting up Santos for a crucial third in the 69th.
A returning Luke Amos stole the ball off Denis Genreau and set up youngster Khoa Ngo to give Glory some late hope, but Victory were able to hold out, moving up to fifth in the A-League Men table, just three points behind leaders Auckland..
As well as denying Perth four straight road triumphs for the first time in the A-League era, the result also secured Victory four consecutive league wins for the first time since a Kevin Muscat-led side won six in a row in 2018-19.
"We've been talking a lot this last month or so about every player being the best version of themselves," said Diles.
"If they do that, then the team's always going to be so powerful and so strong.
"They're doing that, and that's credit to them, but they've got to keep going."
Beyond Mata making it four assists in four games, D'Arrigo's goal was his first for Victory, while Velupillay scored his first for the season, with Socceroos' coach Tony Popovic in the stands to observe the World Cup hopeful fire in his deflected volley.
"We are improving," Mata reflected. "Yes, we are playing well and getting results and momentum, but I think we can still do better."
The one major downside for Victory was an injury to skipper Roderick Miranda, who will get scans after feeling pain behind his knee and being forced off shortly after Glory's opener.
While able to make a game of it thanks to Ngo's first A-League goal, Perth were left ruing a breakaway one-on-one chance to Arion Sulemani that would have put them 2-0 up if not for a last-gasp save from Jack Duncan.
"You get that second goal, and it's a very good first half performance," Glory boss Adam Griffiths mused.
"When you finish this game, and you're disappointed that you didn't win, that shows that we're going in the right direction. But it's still not good enough."
Perth remain in ninth spot as they prepare to head back west for a two-game homestand.
