St Kilda had trailed by as much as 27 points at RSEA Park on Sunday before Wardlaw slammed through three straight goals in the final quarter.
With just two points the difference, Georgia Patrikios launched St Kilda ahead for the first time en route to an 8.5 (53) to 6.6 (42) victory.
Port's Sachi Syme had given Patrikios a free kick after holding the Saints forward, but Piper Window made matters worse when she incorrectly handed the ball to Syme instead.
Gifted an extra 50 metres, Patrikios hit the scoreboard easily, before Amber Clarke added the cherry on top.
The Saints kicked six goals to none in the final quarter.
Nick Dal Santo's St Kilda have won three on the trot and can move as high as seventh (4-3), while Port Adelaide languish in 14th (2-5) with just five games remaining of the 12-round season.
Wardlaw finished with a game-high four goals from 13 touches and eight marks, while Tyanna Smith led the way in the midfield with 24 disposals and five clearances.
Saints captain Hannah Priest overcame a broken nose to finish out the game after copping a heavy knock from teammate Smith in the second quarter.
Abbey Dowrick (17 disposals, six clearances) was Port's best in the contest, while Matilda Scholz (30 hitouts) dominated in the ruck.
Gemma Houghton also kicked two goals for the Power.
Port Adelaide were busy early and kicked four goals to one point in the opening term.
Window kicked off proceedings with a sensational goal from outside the 50-metre arc, helped after teammate Indy Tahau selflessly shepherded Saints defender Nicola Stevens to see Window's ball over the line.
But the Saints rallied after the break and should have done more than halve the deficit to 12 points after enjoying most of the territory.
Lauren Arnell's side responded with a goal each from Katelyn Pope and Tahau to restore lost ground in the third quarter, but the Saints remained dogged.Â