The Capitals finished 0-for-3 on the power play.
"Their goalie obviously played really well," Washington forward Anthony Mantha said. "We're still believers that if you can't see the puck, you're not going to save it. We've got to keep working on the relationship of guys getting to the net, taking the goalie's eyes away, but at the same time [you] have to keep getting pucks to the net."
Oettinger preserved his first shutout of the season with 12 saves in the third.
"I think we knew that we had a starting goalie, but until you come out and do it every night, you always wonder if it's real," Dallas coach Peter DeBoer said. "But it's real. He's the real deal. It's a such a luxury to have a guy like that because he makes hard saves look easy."
NOTES: Stars defenseman Miro Heiskanen missed a second straight game with an upper-body injury. He is day to day. … Capitals forward Alex Ovechkin had a game-high seven shots on goal. He has 783 NHL goals and is three shy of tying Gordie Howe for the most with one team. Howe scored 786 with the Detroit Red Wings.