Rule No. 1 in the Eastern League Western Division Series is to survive and advance.

Rule No. 2 is when you have the reigning champs on the ropes, land a haymaker and make sure they stay down.

The RubberDucks tried to do that Friday at Peoples Natural Gas Field in Altoona but just missed as the Curve came back to force a Game 4 with an 8-5 win.

The Ducks still hold a 2-1 lead in the series, but now must come back at 4 p.m. Saturday.

“It’s just a tough night,” Ducks manager Tony Mansolino said. “You have to give Altoona credit. They’re a really good team over there. We feel really fortunate to be up 2-0 going into the game and now 2-1 after it. We knew it was going to be tough to get through it. Fortunately, we won the two games at home going into [Saturday].”

Everything looked like it was going to go swimmingly for the Ducks after a five-run first immediately put Altoona on its heels.

The outburst was highlighted by a three-run double by Andrew Calica and a triple by Mark Mathias.

But Altoona was able to chase Zach Plesac from the game in the fifth in favor of R.C. Orlan.

Cole Tucker, who homered in Game 2, greeted Orlan with a two-out grand slam to tie things at 5-5.

It stayed that way until the eighth when the Curve loaded the bases with one out.

Nick Pasquale came in and Logan Hill put Altoona up for good with a fielder’s choice back to the mound.

Altoona added two more in the inning, and Matt Eckelman came in to close things out.

Indians third baseman Josh Donaldson, who hit a two-run home run in Game 1, batted second in Game 3. The 2015 AL MVP went 0-for-4 with two strikeouts.

He can come off the disabled list on Sept. 11.

The Ducks will try to close the series out on the road Saturday when right-hander Sean Brady (7-7, 4.53) faces Curve right-hander Dario Agrazal (5-6, 3.99).

“I don’t think one game is more important than the other,” Mansolino said. “Every pitch, every day, every game, they’re all important. You just have to go out there and try to lock in as much as you can and play each pitch the way you should and see what happens.”