Dallas and Washington are on the cusp of playoff positions, but while the Stars appear to be seizing their opportunity, the Capitals' slump has them drifting closer to missing the postseason for the first time in seven years.
Dallas seeks a fifth win in six games Tuesday night when it visits Washington.
The Stars (36-27-11) dropped four straight March 14-20 but have since won four of five to pull within a point of Phoenix for the second wild-card spot in the Western Conference as they seek their first postseason appearance since 2008.
Washington (34-28-13) has reached the postseason each year dating to 2008 but trails Columbus by one point for the final East wild-card spot after dropping three in a row and four of five.
Dallas had lost six of seven away from home prior to a 4-2 win Saturday over St. Louis in the opener of a five-game trip. Colton Sceviour scored two goals, but Tyler Seguin's 11-game point streak came to an end and fellow top-line forwards Jamie Benn and Valeri Nichushkin failed to record a point. The Stars had been 2-10-3 when the Seguin-Benn-Nichushkin trio went without a point.
The victory marked Dallas' second over the West-leading Blues in March.
"I don't know if desperation is the word. That kind of sounds bad," said Sceviour, who also had a goal and an assist in Friday's 7-3 win over Nashville. "But definitely we feel like these are games we need to win. This is a start and we want to build off it."
The Capitals lost 4-3 in a shootout Sunday in Nashville. Troy Brouwer scored twice for Washington, which was 2 for 4 on the power play after going 2 for 13 in the previous four games.
"I thought we played better today than yesterday," coach Adam Oates said, referring to a 4-2 loss to Boston on Saturday in which his club fell behind 3-0. "There were moments where we didn't execute, but I thought that as we got into the game, we played better."
Alex Ovechkin failed to record a point for the fourth time in five games, and it was also Washington's third shootout loss in its last five. The Capitals have played in a league-high 19 shootouts, losing seven of their last eight after winning eight of the first 11. Their 25 wins in regulation or overtime are only more than Edmonton, Florida, Buffalo and the New York Islanders - teams well out of playoff contention.
"There aren't enough games left to be too positive about only getting one point," said defenseman John Carlson, who recorded his 23rd assist Sunday. "Yeah, it is a point, but it's only going to make our road harder."
Dallas' Kari Lehtonen, who stopped 33 shots against St. Louis, has won his last three starts versus Washington behind a 1.33 goals-against average.
The Stars' 2-1 home win over the Capitals on Oct. 5 marked their fourth straight in the series.