By virtue of the victory, Advance defends its district title against perennial champion Oran on Thursday.
"We feel very fortunate to get to go on," said Advance coach Bob Moses. "We played good baseball against a very good team. Now we've got Oran. They're well coached, they don't make mistakes and they have a bunch of classy kids. We're just going to have to play (well)."
Advance (12-3) was fortunate, indeed, scoring an unearned run to tie and another unearned run for the gamewinner.
Chaffee (10-15) took the early lead on Josh Steger's two-run homer to left field in the first inning.
"We got two runs in the first inning and you don't want to relax," said Chaffee coach Brian Horrell. "I thought we should have put some more runs on the board."
Chaffee put leadoff runners aboard in the third, fifth and sixth innings, but came up empty each time.
Advance crept within one on Jeremy Limbaugh's RBI double in the bottom of the first to narrow the gap to 2-1.
In the third, Advance's Rusty Hendricks singled, then stole second. Red Devils' catcher Adam Uhrhan's throw on the steal attempt was on target but muffed at second, allowing Hendricks to advance to third.
Trenton Moses followed with a grounder to third for the potential third out, but a wide throw pulled the first baseman off the bag as Hendricks trotted home with the tying run.
A similar situation developed in the fourth inning when Advance scored what proved to be the game-winning run.
Daryl Wade led off with a single and Uhrhan's throw on a steal attempt appeared once again to be in time and on target for the putout. But, again the ball eluded a Chaffee infielder and Wade slid in safely.
"Two runs that scored were thrown out at second base," said Horrell. "If we get those two kids out, it could have been different, but you've got to give them (Advance) credit. They put the ball in play and they were aggressive on the bases."
Wade later advanced on a groundout, then scored on a booted groundball for a 3-2 Advance lead.
"You've got to do it when it counts; a break here or a break there can mean all the difference," said coach Moses.
Chaffee posed one final threat in the top of the seventh when Chris Hanback lined a two-out triple down the right-field line, but was stranded.
Chaffee's ace Steven Dooley took the hard-luck loss. He went the distance and gave up one earned run on four hits with seven strikeouts, no walks and one hit batsman.
"Dooley deserved a better fate," said Horrell. "Runs were at a premium today and we just didn't get the big hit. We had opportunities. We just didn't get it done and they made the most of theirs (opportunities)."
Wade picked up the win and Limbaugh earned the save with two scoreless innings.
Wade went five innings, giving up two runs on three hits with eight strikeouts, three walks and one hit batsman. Limbaugh issued one hit with four strikeouts and one walk.
Hanback went 2-for-3 to lead Chaffee. Steger's homer and Daugherty's single accounted for the other Red Devil hits.
Hendricks, Moses, Wade and Limbaugh split the four Advance hits.
Advance and Oran meet on Thursday at 4 p.m. on Oran's field.