Opening the Priestman era with two draws, the Phoenix broke through for their first win of the A-League Women season after teenager Pia Vlok's 39-minute goal at Porirua Park on Sunday.
At Leichhardt Oval, Sydney FC surged to the top of the table thanks to Maddie Casper's match-winner in a bitter 1-0 clash against reigning champions Central Coast.
Wellington had started round four of the women's competition dead-last in 11th place after just two draws, but now sit fifth behind the second-placed Victory (2-0-2).
Sunday's result was also their first win in a total of eight meetings with last year's grand finalists Victory.
Vlok had found the back of the net after Victory goalkeeper Courtney Newbon fell attempting to intercept Manaia Ellott's cross.
A full-stretch Newbon had pulled off a stunning save in the 21st minute to deny Phoenix star Elliott, who had unleashed powerfully from the edge of the box.
The visitors enjoyed most of the ball but couldn't make any of their 18 shots count against a stingy Phoenix defence.
Later on Sunday, Sky Blues youngster Caspers broke the deadlock in the 76th minute after Mariners defender Elizabeth Barwick-Grey failed to clear the ball out of the box.
Sydney FC captain Sarah Hunter pounced first and set up Caspers from just outside the box for the match-winner.
Amid positive signs for the rebuilding heavyweights, Sydney FC moved to the top of the table (2-2) and are one point clear of Newcastle.
Ante Juric's Sky Blues had last year missed out on finals action for the first time in the competition's 17-year history after finishing eighth.
Meanwhile, Central Coast are ninth (1-0-3) in their championship defence.
Set up by Tiana Fuller, Barwick-Grey had a chance to salvage a point three minutes into added time but her shot from the centre of the box went just wide.
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