Both the Petaluma High School baseball and softball teams advanced to the finals of the Sonoma County League playoffs with victories in semifinal games Tuesday.

The post-season tournaments involve the top four finishers in the regular season in a single-elimination tournament that has no bearing on the final standings.

Playing under the lights at Arnold Field in Sonoma, the Petaluma baseball team played what Trojan coach Jim Selvitella called his team’s “most complete game of the year” in beating El Molino, 10-0, in a game halted after six innings.

The Trojans had 15 hits in the game, with Devin Gottschall going 3-for-4 with a double and two RBIs; Kempton Brandis belting three hits and scoring two runs; Porter Slate slugging a double and a single and driving home a run; Danny Marzo singling twice and driving in a run; Garett Lewis doubling and driving in a run; and Bradley Smith slugging a triple and driving in a run.

Petaluma will play the winner of Wednesday’s game between Analy and Piner on Thursday at 7 p.m. at Arnold Field.

The Petaluma girls scored six runs in the sixth inning to defeat Piner, 12-2, in a game played at Analy High School.

Mandi O’Keefe and Kaleigh Weiand each had two hits to lead an 11-hit Petaluma assault. Weiand belted a double and a home run, scored three runs and drove in two.

Rachael Bles pitched five strong innings, allowing just four hits, while not walking a batter and striking out three.

Petaluma will play either Sonoma Valley or Analy at 5 p.m. Thursday.

The Casa Grande girls lost a marathon heartbreaker in the semifinals of the North Bay League Tournament, finally yielding to Rancho Cotate, 10-8, in 10 innings.

The Casa Grande boys were to play at home Wednesday against Rancho Cotate. Results of that game were not available at press time.