Hossa's goal late in the second period gave the Blackhawks their first lead at 4-3. He added an empty-net goal with 16 seconds left that turned out to be the game-winner after Toronto's Mike Brown scored with 4 seconds remaining.
The Blackhawks have dived from first in the NHL on Jan. 20 to sixth in the Western Conference. During the slide, Chicago's highly skilled, highly-paid offensive stars -- especially Kane -- often haven't performed up to expectations.
But on Wednesday, both Kane and Hossa battled through traffic and controlled the puck to spark the Blackhawks' comeback.
"I think Kaner had an excellent game," Chicago coach Joel Quenneville said. "I look back over the season and this game stands out as far as puck possession, threat to score off the rush, in-zone, time of possession.
"Offensively and defensively he had a real purpose, liked his leadership as well. Our top guys have got to be, not just our best players, but they have to lead us through this stretch here."
Kane scored for the second straight game, but only for the fifth time in his last 25.
"We'll try to get some wins, get some points and try to finish the season strong," Kane said. "For sure, we're desperate. We're in the back half of the West, so how can you not be."
Rookies Marcus Kruger and Andrew Shaw also scored for Chicago.
Tyler Bozak, Joffrey Lupul and Clarke MacArthur scored in the first period for the slumping Maple Leafs, who lost their sixth straight and 10th time in the last 11 games. Toronto was unable to hold on to a 3-1 lead it built by late in the first.
"We've been talking about how bad our starts have been, and we got the start we wanted, and then let them back into it," Maple Leafs defenseman Luke Schenn said. "A couple goals there that we shouldn't give up, not blaming the goalie, just everyone in general. When you get a lead you've got to clamp down."
Chicago's Corey Crawford started in goal, but was replaced by Ray Emery to start the second after allowing three goals on 10 shots. Emery was sharp and stopped 23 of 24 shots.
"Ray did an outstanding job," Quenneville said. "You look back over the year, you get some goalie wins and Ray was instrumental in us winning tonight."
"We can't really give up," Gustavsson said. "I know no one on this team is going to do that."
Even in another loss, some Toronto players saw encouraging signs.
"Looking back a couple games, I thought this was a step forward, at least how we played the game," defenseman Carl Gunnarsson said "We did some mistakes in our own end and they took advantage of it, but we had some chances tonight."
Blackhawks captain and leading goal scorer Jonathan Toews missed his fifth game with an upper-body injury, believed to be a concussion. Defenseman Niklas Hjalmarsson sat out his third straight and 10th in his last 11, with concussion symptoms.
Defenseman Johnny Oduya, acquired by Chicago from Winnipeg just before Monday's trade deadline, played his first game with Chicago.
The Blackhawks went 0-for-2 on the power-play and have scored just one goal in their last 41 chances.
The Maple Leafs led 3-2 after a first period that mirrored the recent play and records of the two teams.
Bozak opened the scoring 59 seconds in from the side of the net with a soft goal when he slipped a backhand shot under Crawford's pads.
Shaw tied it at 1 with 8:59 left in the first when he drove from the left corner into the slot and beat Gustavsson between the pads. Shaw connected in his first game after being recalled from Rockford of the AHL for the second time this season.
Lupul's power-play tip in just 28 seconds later, set up by Phil Kessel's pinpoint feed, restored the Maple Leafs' lead at 2-1.
MacArthur made it 3-1 with 3:07 left in the first. After Mikhail Grabovski's shot struck the skate of Blackhawks defenseman Brent Seabrook, MacArthur shoveled in the loose puck before Seabrook could find it.
Kruger's deflection of Nick Leddy's shot from the point cut it to 3-2 with 30 seconds remaining in the period.
It was a huge play and got us back to within one," Kane said. "We had a great second period."
Chicago led 4-3 after two periods thanks to goals by Kane and Hossa on strong efforts.
Kane tied it at 3 at 8:33 of the second. He pounced on a rebound of Andrew Brunette's shot, plowed into traffic and flipped in a high shot from a sharp angle to Gustavsson's left.
Hossa gave Chicago its first lead at 4-3 just over four minutes later. After driving down the slot and past two Toronto defenders, Hossa fired a shot just inside the left post.
Emery made a tough kick save on Toronto rookie Matt Frattin with 4:30 left in the third to preserve the lead.
NOTES: Blackhawks LW Brandon Bollig appeared in his first NHL game following his recall from Rockford on Tuesday. He fought Toronto's Luke Schenn. ... Chicago D Steve Montador missed his 11th game with an undisclosed upper-body injury. ... Toronto C Matthew Lombardi was a healthy scratch for the first time this season. He has just one goal and two assists in his last 15 games and is a team-worst minus-13. ... The game was the only one this season between Chicago and Toronto, both Original Six franchises. The teams have not played more than once in season since 2001-02 and over the last nine seasons have met only seven times.
Saturday, March 3
@ Montreal Canadiens
7PM ET (CBC, AM640)
The Maple Leafs play their second straight road game against an Original Six opponent this time their biggest rival, the Canadiens.
Montreal has won three straight against the Leafs but they had lost five consecutive games before facing Minnesota Thursday.
1 - 0 TOR
1 - 1 Tie