Fremantle has set up an intriguing RAC Derby with its second win of the season, bouncing back to hold off a charging St Kilda by five points at Optus Stadium on Sunday.
But Freo might have to take on the reigning premiers without captain Nat Fyfe after the superstar midfielder came from the ground after a head clash and didn't return.
Fremantle were made to earn Sunday's win, with the spirited Saints scrapping all day before eventually going down 11.5 (71) to 9.12 (66) in their first loss of the season.
The visitors trailed by only six points at the final change in a low-scoring clash, but small forward Brandon Matera emerged to boot back-to-back goals at the start of the fourth to give Fremantle some breathing space.
Red-time goals from Jade Gresham and then Jack Billings with eight seconds remaining set up a critical final centre bounce, but the Dockers held on after the umpires spotted an extra man in St Kilda's forward line and forced a reset in the 6-6-6 formation.
Ross Lyon's men will be underdogs when they take on West Coast next Saturday night, but the win gets the Dockers back on track after a disappointing loss to Gold Coast in round two.
Michael Walters was superb for the winners, carving through the midfield to finish with 27 possessions at 92 per cent efficiency, two goals, and eight clearances as a clear best-on-ground.
Defender Luke Ryan (32 possessions, 13 marks and nine rebounds) was crucial marshalling the backline and mopping up the Saints' forward entries, while Ed Langdon (29 possessions) was prolific early.
It was a quiet day for key forward Jesse Hogan, who spent more time forward but was scoreless and is yet to kick his first goal for the Dockers.
Fyfe was excellent in the midfield before colliding with Josh Battle in a fair contest for the ball that resulted in a serious head clash.
The skipper was helped from the ground by two trainers and staggered as he made his way to the interchange gates, putting his availability in question for the Derby.
Fremantle had the game on its terms early, controlling possession and showing glimpses of the exciting brand it opened the season with against North Melbourne.
Freo dominated field position and went inside 50 20 times to six but were unable to take full toll, kicking just three goals to lead by 13 points at the first change.
Unable to generate any attacking movement in the first quarter, St Kilda lifted in the second on the back of its contested game, kicking four straight goals into half-time to cut the margin to five points.
The Saints battled all day but lacked touch when going inside 50 and then in front of goal.
Gresham (20 possessions and two goals) was critical during their periods on top, while Billings (32 and two) continued a strong run of form.
Ruckman Rohan Marshall controlled the air with 40 hitouts and paired that with a presence at ground level with six clearances.
FREMANTLE 3.2 6.2 9.2 11.5 (71)
ST KILDA 1.1 5.3 7.8 9.12 (66)
GOALS
Fremantle: Matera 3,Taberner 2, Walters 2, Hill, McCarthy, Hughes, Lobb
St Kilda: Gresham 3, Membrey 2, Acres, Bruce, Billings, Lonie
BEST
Fremantle: Walters, Ryan, Langdon, Hill, Cerra, Fyfe
St Kilda: Gresham, Billings, Geary, Marshall, Newnes
INJURIES
Fremantle: Fyfe (concussion)
St Kilda: Nathan Brown (head knock)
Reports: Nil
Umpires: Margetts, Fisher, Mitchell
Official crowd: 38,227 at Optus Stadium
