"It was a pretty even game, and we had chances to win, but we scored two and let them get three," Zetterberg said. "It's frustrating because we played well and didn't get anything out of it."
Detroit (24-25-9, 57 points) is seven points behind the New York Islanders and Carolina Hurricanes in the race for the second wild card into the Stanley Cup Playoffs from the Eastern Conference.
"We can't keep giving away points," Red Wings coach Jeff Blashill said. "We've been better about that in the last few games, but we gave away two more tonight."
Detroit nearly took the lead at 8:15 of the first period, but Nyquist couldn't sweep a bouncing puck into the net with McElhinney out of position.
"It's tough because we had opportunities," Nyquist said. "We just need to start finishing more chances."
Zach Hyman put the rebound of a Matthews shot into the net at 11:30, but the play was blown dead when Mrazek shook off his damaged mask.
"I'm not even sure what the rule is in that situation, when the goalie shakes off his mask," Maple Leafs coach Mike Babcock said. "Obviously, player safety is always the most important issue."
Mantha gave the Red Wings a 1-0 lead with a power-play goal at 5:51 of the second period, tipping Nyquist's shot past McElhinney for his 20th goal.
"Obviously, it feels great to get 20, but I don't want to stop here," said Mantha, whose previous NHL career high was 17, in 60 games last season. "I need to keep going."
Van Riemsdyk deflected defenseman Jake Gardiner's shot past Mrazek to tie it 1-1 at 7:02.
The Maple Leafs took a 2-1 lead 18 seconds later when Marner took a pass from Nazem Kadri, outwaited Mrazek, and scored from the bottom of the left face-off circle at 7:20.
