The West Coast Eagles contingent playing for East Fremantle played decisive roles in helping the Sharks plot the first defeat of the WAFL season on West Perth on Sunday.

The Falcons won the first eight games of the season, but East Fremantle produced an irresistible second half to run over the top of the home team to construct an impressive 15-point victory.

Midfielders Bradd Dalziell, Koby Stevens and Tim Houlihan and defender Jacob Brennan were all prominent as the Sharks rattled on eight goals to three in the second half, on the way to an important 13.8 (86) to 10.11 triumph which entrenches them in the top four.

The upset gives East Fremantle a two-game cushion over fifth-placed Perth, who manufactured an upset of their own against Subiaco.

Keys to the East Fremantle win were again the ball winning ability of Stevens, Dalziell and Houlihan, who each accumulated close to 30 possessions and maintained pressure around the midfield, while Brennan was assigned the task of minding experienced West Perth forward Anthony Tsalakis and performed the task well.

Andrew Strijk was in good touch for the Falcons, but like many of the West Perth players, was a little quiet in the final term as East Fremantle took charge. Strijk had 19 possessions and kicked a goal, but also took 10 marks and laid four tackles.

Claremont also scored an important come-from-behind win against Swan Districts, with West Coast players wielding an influence over the result.

Brett Jones was again strong and resilient across half-back with 20 possessions and 10 marks, while Lewis Stevenson was efficient with his ball use from the back half and Gerrick Weeddon was a tireless worker up forward where his defensive pressure was outstanding.

Small forward Lewis Broome had a quiet day, but still managed to kick a couple of important goals in the last quarter.

Developing forward Anton Hamp played in the reserves and kicked three goals from 18 touches and seven marks in another impressive display. Ryan Neates returned from the long-term injury list and played just 60 minutes, which will serve him well as he begins to progress in the second half of the season.

Peel trio Jordan Jones, Scott Lycett and Blayne Wilson produced solid performances as the Thunder gave South Fremantle a fright. Jones played at centre half-back and was opposed by West Coast teammate Callum Wilson and won the points in a good duel.

Jones had 20 possessions and four marks, as well as five tackles, while Wilson struggled to impact, racking up 12 possessions and a goal. Lycett continues to develop as a ruck-forward and had 13 possessions and eight marks as well as a significant number of ruck knocks.

Blayne Wilson played deep back and was strong and resilient.

Andrew Gaff was under notice early for South Fremantle, but suffered hamstring tightness and did not play the second half.