Harker, the defending Central Coast Section champion, beat Castilleja 224-236 at Bay View Golf Club on Monday in a duel of undefeated WBAL teams.
Castilleja's Norah Yang shot a 38 to earn medalist honors and Joanne Zhao scored a 39 despite wind conditions of up to 22 miles an hour, which also affected putts.
Castilleja (9-1) meets Notre Dame Belmont at Golf Club at Moffitt Field on Wednesday. Harker (8-0) and Casti meet again on Wednesday, Oct. 20 at Sunnyvale Golf Club.
Alanna Lee shot a round of 38 and Catherine Chu came in with a 39 but Gunn fell to second-place Lynbrook 195-206 in a SCVAL girls golf match Monday.
Athina Chen and Namya Kasturi each fired rounds of 41 while Stephanie Yang finished with a 57. Kira Kuartei also played for Gunn (4-4-1), which meets Saratoga in the regular season finale Thursday at Baylands Golf Links.
Palo Alto (10-0, 9-0) looks to complete its fifth consecutive undefeated season Wednesday with a match against Los Gatos at Santa Teresa Golf Club.
The SCVAL tournament will be held at Santa Teresa GC on Tuesday, Oct. 19, with a tee time of 11:30 a.m.
Palo Alto, which beat WCAL leader Valley Christian 189-192 last week, won the state title in 2019 but were denied a chance to defend its title due to a ruling from the SCVAL Board of Managers. No SCVAL teams were allowed to play at the CCS tournament in June.
Paly's Sydney Sung was the CCS individual champion in 2019 and returns, along with Lauren Sung and Bridget O'Keefe, from the state championship team.
Saint Francis (9-1, 8-1) ends its regular season with a match against Valley Christian (9-1, 8-0) Thursday at Los Altos Country Club.