Seattle lost for the third straight time at home after opening 5-0 in games at the University of Washington and in nearby Everett as KeyArena undergoes renovation.
The A’s won for the sixth time in seven games and Anderson put a cap his strong first half of the season.
Seattle’s Tommy Milone (1-3) was solid for five innings following opener Matt Carasiti, but ran into trouble in the seventh.
St. Louis entered the ninth trailing 2-0 after a masterful performance from Seattle starter Mike Leake, who threw 7 2/3 shutout innings against his former team for the first time.
Mercedes Russell set a career high with 19 points for Seattle (8-7). Natasha Howard added 15 points, six rebounds and four steals and Sami Whitcomb chipped in with 13 points.
Bellingham gets shut out in series opener
Beckham and Narvaez get long balls in win
Guard gets one-year deal with the Wizards
20 home runs are enough to get slugger his first A-S appearance
Viola’s 9th inning home run make the difference
