Riverside won PIAA titles the past two seasons.
Monday, Shady Side Academy ended Riverside's season much earlier.
Chris Sawicki went 4 for 4 with four RBIs and No. 14-seeded Shady Side Academy stunned No. 3 Riverside, 9-2, in a WPIAL Class AA first-round playoff game at Highlands.
Coming into the game, Riverside (15-4) had won six games in a row; Shady Side Academy (13-7) had lost three consecutive.
Paul McCullough was the winning pitcher for the Indians, who led, 8-0, after three innings.
Other Class AA
• Quaker Valley 6, Burrell 3: Nelson Westwood had three RBIs, including a two-run triple in the first, as the top-seeded Quakers (19-0) beat the Bucs (8-9) at Hampton.
• Chartiers-Houston 7, Steel Valley 5: Dylan Pounds was the winning pitcher and drove in the go-ahead run with a single in the fourth to help the Bucs (12-7) overcome a 5-2 deficit to defeat the Ironmen (12-6) at Upper St. Clair.
• Laurel 1, Washington 0: Brandon Ritchie fired a two-hitter with 13 strikeouts in helping the Spartans (10-7) edge the Little Prexies (11-6) at Chippewa Park.
• Freeport 9, Brownsville 4: Robbie Miller had three hits, including a two-run triple in the second, to lead the Yellow Jackets (12-3) to the win against the Falcons (13-5) at Mount Pleasant.
• Greensburg Central Catholic 12, New Brighton 11: The Centurions (13-5) broke a 7-7 tie by scoring five runs in the sixth and went on to defeat the Lions (13-5) at Hampton. Greensburg C.C.'s Garrett Brooks had three RBIs.
• Deer Lakes 2, Seton-LaSalle 1: At Highlands, the Lancers (16-3) advanced with a victory against the Rebels (8-9). The Section 3 champion Lancers have won 15 of their past 16 games.
• Beaver 6, Bentworth 5: The Bobcats (14-3) edged the Bearcats (10-6) at Chartiers Valley. The Bobcats have won five consecutive games.
• Serra Catholic 3, Springdale 0: Wayne Hydak tossed a three-hitter with 10 strikeouts to lead the No. 1-seeded Eagles (17-1) to a victory against the Dynamos (6-8) at CCAC-Boyce.
• Our Lady of the Sacred Heart 12, Monessen 0: Tim Mulvey threw a two-hitter to propel the Chargers (17-2) to the triumph at Burgettstown. Monessen (6-12) was playing in its first playoff game since 1987.
• California 7, Sewickley Academy 4: Michael Luketich went 4 for 4 with two RBIs and two runs scored in helping the Trojans (16-4) defeat the Panthers (10-6) at Burgettstown.
• Western Beaver 6, Jefferson-Morgan 5: The Golden Beavers (15-2) raced to a 6-1 lead and hung on to defeat the Rockets (11-5) at Chartiers Valley. Robert DiMaggio had two hits and two RBIs for Western Beaver.
• Carmichaels 10, Frazier 0: Brandon Lawless gave up two hits and struck out seven to lead the Mighty Mikes (13-3) to a six-inning win against the Commodores (7-12) at Mount Pleasant.
• Riverview 9, Rochester 4: Jake Paradise and Zach Aber had three RBIs apiece and the Raiders (15-2) advanced with a victory against the Rams (6-9) at Fox Chapel.
• Bishop Canevin 16, Vincentian 1: The Crusaders (8-5) had little trouble on their way to the four-inning win against the Royals (12-6) at Highlands.mobilehome - hsbaseball