Jordan Binnington made 25 saves for St. Louis, which is 2-4 at home in the Stanley Cup Playoffs.
"A loss is a loss, it doesn't matter where it is," Schwartz said. "It's obviously tough, but we feel confident about bringing it back here. It has to be our best game."
The Stars would advance to the Western Conference Final with a win at home in Game 6 on Sunday.
"We just have to collect ourselves, get some rest, and get ready for a game," Spezza said. "It's going to come quickly with the afternoon game. We have a good opportunity to close out the series on home ice, and we have to make the most of it."
Spezza gave Dallas a 1-0 lead at 2:42 of the first period with a one-timer from the slot off a Tyler Seguin pass from behind the net after Binnington made a point-blank save on Mattias Janmark. It was his third goal of the series.