The Western Conference final is headed back to California.
Saad made a nice pass to the middle and Handzus beat goaltender Jonathan Quick with a backhander for his second goal of the playoffs. The Slovak center celebrated by pounding the boards behind the net as the sellout crowd of 21,871 roared.
''I saw him for a second there, and threw it,'' Saad said. ''He handled it off his skate and made a great move. It was all good on him. He's a leader out here, does all the right things, so it's good to see him get rewarded.''
Handzus has been all over Chicago's lines all season long as the Blackhawks searched for a second-line center behind captain Jonathan Toews. His biggest value right now is on the penalty kill, but it was his offense that kept Chicago's title defense alive.
''I want to help the team as much as I can,'' Handzus said. ''I'm playing on the PK a lot. I'm not playing very well offensively. I'm glad I came through.''
''Personally, I thought Saader was the best player on the ice tonight,'' Kane said. ''He was bringing so much speed and puck protection.''
Game 6 is Friday night in Los Angeles.
''We go home and we come out with a better effort,'' Kings defenseman Jake Muzzin said. ''We've got some experience and veterans in here who know what it takes to stop it.''
Marian Gaborik and Dustin Brown each had a goal and an assist, and Jarret Stoll and Tanner Pearson also scored for the Kings, who led 4-3 after two periods. It was Gaborik's NHL-best 11th playoff goal.
Quick and Chicago's Corey Crawford each stopped 40 shots.
Los Angeles was in position to advance to its second Stanley Cup Final in three years before Smith drove to the net and swept in a rebound 1:17 into the third. Smith's third goal of the playoffs set the stage for a frantic finish as both sides pushed for the winning score.
''It's not easy,'' Kings forward Justin Williams said. ''Attaining your ultimate goal is never easy and we're going to do our best to get it done.''
Quick made a solid stop on Marian Hossa in overtime, and the loose puck was swept away by the Kings. Los Angeles star Anze Kopitar had a chance to win it about 9 minutes into the first overtime but his shot went off the side of the net.
Crawford had a kick save on Stoll in the first OT after Toews turned it over in the Blackhawks' zone.
''Overtime, I've seen a lot of games, been involved in a lot of games,'' said Chicago coach Joel Quenneville, a former NHL defenseman. ''That might have been the greatest overtime I've seen.''
Back at home for Game 5 after a disastrous stay in Los Angeles, the Blackhawks put together a terrific start. But the Kings weathered the storm and then stepped up their attack in the last part of the first period.
Seabrook, Oduya and Saad helped the Blackhawks take a 3-1 lead just 11:06 into the game. Chicago's second line of Saad, Andrew Shaw and Kane was a headache for Los Angeles all night long, creating numerous high-quality scoring chances.
But the Kings regained the momentum on a terrific sequence with 7 minutes left in the first. Quick made a great stop on Toews, and Kopitar set up Gaborik at the other end to get the Kings within one.
It was reminiscent of Game 2, when Quick denied Seabrook on a 2-on-1 and the Kings went on to score six straight goals in a 6-2 victory.
This time, Brown had a nice rebound goal after Crawford made a great save on Gaborik, and Pearson made it 4-3 with a wrist shot from the right circle at 13:08 of second. Pearson deftly used Blackhawks defenseman Niklas Hjalmarsson as a screen on his fourth goal of the playoffs.
Quick also had an outstanding save on Saad from inside the goal early in the second.
Pearson's goal stunned the crowd, but it woke up again when Saad's perfectly timed shot set up Smith's tying score. Saad had a plus-4 rating in almost 24 minutes of ice time in one of the best games of his young career.
NOTES: Los Angeles police say they are investigating a battery report from a fan who says Crawford sprayed water in his face during Game 4 at Staples Center. The report alleges Crawford used a water bottle to spray the face of the heckling fan, who was thrown out of the arena and later filed the complaint with police. ... Kings D Robyn Regehr missed his 11th straight game with a knee injury.
Jay Cohen can be reached at http://www.twitter.com/jcohenap