The Leafs, who were playing at home for the first time since Feb. 6 following a season-long six-game trip that ended with a 3-2-1 record, entered 7-2-2 over their last 11, but had also dropped two straight.
The Capitals, meanwhile, were 6-3-1 over their previous 10 after a 0-5-2 stretch that culminated with a 6-3 loss at Scotiabank Arena on Jan. 23.
Brent Burns picked up his 12th of the season, and Evander Kane added a short-handed goal for the Sharks, who beat Casey DeSmith three times in the opening 14 minutes and kept the Penguins in check the rest of the way to sweep the season series from the team that edged them in six games in the 2016 Stanley Cup Final.
The Sharks have won eight of 10 overall and pulled within one point of Calgary for the top spot in the Pacific Division.
DeSmith finished with 29 saves, but Pittsburgh stumbled out of the gate and never recovered to lose for just the second time in six games.
NEWARK, N.J. (AP) — Cory Schneider made 30 saves in posting his first shutout since November 2017 and New Jersey beat undermanned Ottawa in a game in which both teams gave indications they were getting ready to make trades in the next few days.
DALLAS (AP) —Jamie Benn had his first multi-goal game since early October and Dallas ended St. Louis' franchise-record 11-game winning streak.
When Benn scored the game's first goal 3:46 into the second period, the Blues trailed for the first time since Feb. 5 — a span of more than 517 minutes on the ice over 10 games.
Radek Faksa and Alexander Radulov put Dallas up 3-0 with goals in a 65-second span midway through the second period. Tyler Seguin also scored for the Stars, who snapped a three-game losing streak in which they were shut out twice. Anton Khudobin stopped 43 shots while starting his seventh consecutive game for the Stars.