The Power remain 12th, but just six premiership points shy of the top eight, after a 17.10 (112) to 6.13 (49) victory at Adelaide Oval.
forward Chad Wingard booted four goals and teammates Robbie Gray (37
disposals) and Justin Westhoff (23 disposals, two goals) were
instrumental in a win which came with a cost - midfielder Ollie Wines
dislocated a shoulder.
Wines was hurt in the first term of a match preceded by a ceremony in support of Sydney star Adam Goodes.
greats Nicky Winmar, Gavin Wanganeen and Byron Pickett greeted both
captains before play, and then Port's players made St Kilda pay for its
Midway through the second quarter, the Saints had 1.9, including five rushed behinds.
And at half-time they trailed by 25 points despite entering their attacking 50m arc five more times than the Power.
Kilda's skill errors were pounced on by Port, who kicked the initial
three goals of the third term to stretch out to a defining 44-point lead
and then coasted to victory.
With Gray, captain Travis Boak (29
disposals) and backmen Hamish Hartlett (27 possessions) and Matthew
Broadbent prominent, the Power banked an eighth win of the season before
a 36,850-strong home crowd.
Port's defenders, led by Jack Hombsch
who kept Josh Bruce goal-less until he scored after the final siren,
applied a strangle on St Kilda's attackers, with midfielder Leigh
Montagna (two goals) the visitor's sole multiple goalscorer.
Saints, who were well served by Montagna, David Armitage (22
possessions) and Jarryn Geary (23 disposals), also lost ruckman Billy
Longer, who was substituted because of a suspected knee injury.