The best-of-7 series is tied 2-2 heading to Game 5 at T-Mobile Arena on Tuesday (9:30 p.m. ET; ESPN, SN360, SN, TVAS).
Beckett Sennecke and Alex Killorn each had a goal and an assist, Mikael Granlund and Ian Moore also scored, and Lukas Dostal made 18 saves for the Ducks, the No. 3 seed from the Pacific Division.
Pavel Dorofeyev, Brett Howden and Tomas Hertl scored, Mitch Marner had three assists, Jack Eichel had two assists, and Carter Hart made 19 saves for the Golden Knights, the No. 1 seed from the Pacific.
Vegas played without captain Mark Stone, who was out with an undisclosed injury that caused him to miss the second and third periods of Game 3.
Anaheim was on the first power play of the game when Killorn passed the puck from off the wall to Sennecke above the right face-off circle and he scored five-hole with a one-timer to give the Ducks a 1-0 lead at 8:43 of the first period.
The Golden Knights went on their first power play 32 seconds later and Dostal couldn't glove a shot by Marner. The puck fell in the crease and Dorofeyev pushed it into the net to tie it 1-1 at 10:22.
Anaheim moved back ahead 2-1 at 15:25 of the first when Jeffrey Viel backhanded a pass off the wall to Granlund above the right face-off circle. He took a couple strides towards the Vegas net before his snap shot went off the stick blade of Vegas forward Cole Smith and under the right armpit of Hart.
The Golden Knights tied it 2-2 at 4:04 of the second period.
William Karlsson chased down the puck behind the Anaheim net and made a no-look pass out front to Howden, who held off Ducks forward Tim Washe as he chipped the puck into the net from in front of the crease.
Anaheim, which came into the game 0-for-11 with the man-advantage in the series, scored its second power-play goal when Killorn brought the puck along the goal line and banked it off Hart for a 3-2 lead at 17:58.
Moore, who was a healthy scratch the previous two games, scored with a snap shot from above the right circle to make it 4-2 at 3:43 of the third period.
The Golden Knights pulled Hart for the extra skater and Hertl redirected the puck into the net to cut it to 4-3 with 1:04 left.
