Vanessa DiBernardo double led Glory to a 5-1 triumph in a thrilling end-to-end encounter. Glory came from behind in front of 1592 loyal fans as the side made a real statement en route against a Sydney side featuring a host of Matildas stars.
It was an entertaining opening half which saw plenty of chances for both sides as Kerr and Foord were central to almost every attack.
Sydney opened the scoring in the 23rd minute, with Kyah Simon's acrobatic effort bouncing past Gabby Dal Busco.
Glory responded from the spot with DiBernardo coolly slotting home to even the scores, after Georgia Yeoman-Dale was judged to have fouled Alyssa Mautz.
Perth grabbed the lead in the 58th minute, with DiBernardo's dangerous cross proving too much for Alanna Kennedy as she sliced her attempted clearance over Claire Coelho for an own goal.
Perth was not done there, with the home side's class shining through as DiBernardo hit the back of the net again to double its advantage. The American's first shot was blocked, but the midfielder's superb second strike flew passed Coelho to make it 3-1 with 15 minutes to play.
Glory's fast finish continued with Rosie Sutton controlling a ricocheted shot into the back of the net.
The afternoon was capped off with a stunning lob over the 'keeper to send the crowd into a frenzy to help the Glory Women win 5-1.
The convincing victory for Perth will see the team return to the Grand Final for the first time since 2014 and Bobby Despotovski's troops will be looking to claim their first Championship.
Glory will have to wait until Sunday's second semi-final result to determine next week's Grand Final Opponent.
4' Kerr's lobbed pass in the box finds Gibbons in space, but her strike is narrowly wide of the post.
8' Foord makes a darting run into the area and her cutback is palmed away by Dal Busco.
9' Dal Busco is forced into a smart save after Foord's shot was deflected by Simon.
23' Rigby initially blocks Siemsen's close range effort, but Simon's acrobatic effort opens the scoring directly after for Sydney.
28' Mautz run into the area is impeded by Yeoman-Dale and her challenge from behind is judged a penalty which DiBernardo cooly slots home to level the scores.
42' Sutton's first time ball puts Kerr through on goal, but her powerful low shot is saved by Coelho.
45' Khamis makes a dangerous run into Glory's box and her shot rolls under Dal Busco and Rigby clears for a corner.
49' DiBernardo dribbles out wide before cutting onto her left only for her shot to be deflected out.
55' Mautz hits the crossbar but comes off worse for wear as Coelho clocks her in the head trying to spoil.
58' DiBernardo's left-footed cross proved too much for the Sydney defence as Kennedy's attempted clearance loops over Coelho's head into her own net.
63' Sarah Carroll unleashes from 30-yards and forces Coelho into a diving save.
77' DiBernardo doubles Glory's advantage with a superb left-foot volley.
79' Sutton extends Perth's lead with a simple finish after Coelho originally saves Kerr's curling effort.
90+1' Billam makes it 5-1 at the death with an impressive curling finish just under the crossbar.
Perth Glory: 18. Gabrielle DAL BUSCO (GK) 2. Sarah CARROLL, 3. Kim CARROLL, 4. Alyssa MAUTZ, 7. Nicole STANTON, 9. Rosie SUTTON (6. Carla BENNETT 86'), 10. Vanessa DIBERNARDO, 13. Jaymee GIBBONS (8. Shawn BILLAM 71'), 17. Natasha RIGBY, 20. Samantha KERR (C), 22. Arianna ROMERO
Subs not used: 1. Melissa MAIZELS (GK), 5. Patricia CHARALAMBOUS, 14. Caitlin DOEGLAS
Sydney FC: 22. Claire COELHO (GK), 2. Teresa POLIAS (C), 3. Remy SIEMSEN, 4. Elizabeth RALSTON, 6. Servet UZUNLAR, 7. Nicola BOLGER (20. Princess IBINI-ISEI 82'), 9. Caitlin FOORD, 13. Georgia YEOMAN-DALE, 14. Alanna KENNEDY, 17. Kyah SIMON, 19. Leena KHAMIS (12. Olivia PRICE 68')
Subs not used: 8. Amy HARRISON, 10. Francisca ORDEGA, 15. Sarah EASTHOPE (GK)
Yellow Cards: 2. Teresa POLIAS 69'