Max Sapp's walk-off RBI single lifted Tri-City past Auburn, 4-3, on Sunday for a sweep of the New York-Penn League Division Finals.
With the score knotted in the ninth inning, Greg Buchanan lined a leadoff single off Doubledays reliever Patrick McGuigan and advanced on Tim Torres' sacrifice and Eric Taylor's single.
Benjamin Harrison relieved McGuigan and got Jordan Parraz to ground out before Sapp ripped his only hit of the game into right field to plate Buchanan and end the best-of-3 series.
"They were pitching me outside all night," Sapp said. "Finally I got a fastball inside-middle that I'd been looking for and I found the hole."
Buchanan had three hits and scored three times and Torres was 3-for-4 with an RBI single in the first for the ValleyCats.
Tri-City reliever Cesar Mayora (1-0) got the win after striking out four in 1 2/3 scoreless innings. Starter David Qualben gave up two runs -- one earned -- on four hits and a walk while fanning four over six frames.
"Pitching and defense got us here," manager Gregg Langbehn said. "We had a couple close games [against championship opponent Staten Island] lately which will motivate us for the finals."
McGuigan (0-1) yielded one run on two hits in 1 2/3 innings. Auburn starter Kyle Ginley allowed two runs on four hits over three innings, fanning five and walking two.
Matthew Liuzza went 3-for-4 with a game-tying RBI double in the eighth for the Doubledays. Shawn Scobee slapped an run-scoring single, and Raul Barron came home on a balk in the second.
Tri-City hosts Staten Island in the opener of the best-of-3 championship series at 7 p.m. ET on Tuesday.