Wanneroo Wolves caused the biggest upset of the first week of the women's State Basketball League quarterfinals, beating Rockingham Flames 79-74.
The Wolves have two chances to clinch the best-of-three series at Rockingham next week, but it will be a tough ask with the Flames 9-2 at home in the regular season.
Sue Williams and Rebecca Mercer starred with 18 points each for Wanneroo to help the seventh seed overrun Rockingham in the second half, outscoring them 40-27 after half-time.
Kaye Tucker had 21 points and nine rebounds for second seed Rockingham, who have lost three of their past four games, including the regular season.
Perry Lakes Hawks also scored a minor upset with a 78-68 win at 2009 grand finalists Mandurah Magic, putting the Hawks in control of that series.
Despite Perry Lakes finishing the season third, compared to Mandurah's sixth, the Magic were favourites in game one due to their 10-1 regular- season home record.
The Hawks are at home for games two and three next week and should advance, after Tegan Walker (19 points) put them in the box seat of the series, while Casey Mihovilovich (20 points) and Shelley Boston (19 points, 15 rebounds) provided resistance for Mandurah.
Perth Redbacks will be heavily favoured to advance after beating East Perth Eagles 54-47.
The fourth and fifth-placed sides were separated only on the result of head-to-head battles in the regular season but Perth always looked in control, on the back of Marita Payne's 16 points.
The Eagles will have to win twice at Perth next week to advance after a disappointing performance in which only Ashley Gilmore and Samantha Norwood, who combined for 30 points, provided any real resistance.
Top side Willetton Tigers should progress to the semifinals after beating Lakeside Lightning in a 64-62 thriller.
The eighth-placed Lightning gave Willetton a scare when they reduced the margin to three with two minutes left, but the defending champions held their nerve to claim the win.
Kate Malpass (16 points) was among Willetton's best, while Heidi McNeill led Lakeside with 18 points.
In the men's competition, the top four teams won. Though the higher-placed teams in the quarterfinals had to play the first of the best-of-three series away, they overcame any home-court advantage on the weekend.
In fact, there was only one close game, at Joondalup. Perth Redbacks trailed by 15 points with eight minutes left but outscored home team Wanneroo Wolves 38-14 from that point to win by nine.
Lakeside Lightning 98 (Payne 25, Beran 20) d East Perth Eagles 76 (Weigh 27), at Morley
Willetton Tigers 101 (Tovey 31, Prince 22) d Goldfields Giants 68 (Hulme 23), at Kalgoorlie
Geraldton Buccaneers 108 (Zamroz 29, Connelly 22) d Perry Lakes Hawks 91 (Crawford 30, Kempf 25), at WA Basketball Centre
Perth Redbacks 118 (Meriweather 39, Wagner 34) d Wanneroo Wolves 109 (Coverstone 39, Salinas 20), at Joondalup
Quarterfinals, game two: Friday July 30 - Lakeside v East Perth (North Lake 7.30pm), Perth v Wanneroo (Belmont 8.30pm). Saturday July 31 - Willetton v Goldfields (Willetton 8pm), Geraldton v Perry Lakes (Geraldton 7.30pm).