The provincial rivals, who faced each other on Friday night as well, wasted no time showing their dislike for each other as the first of three fights came 18 seconds into the game.
"It was a pretty heated game. Especially after (Friday's) game," said Moose Jaw forward Tanner Eberle, who fought Regina's Dyson Stevenson on the opening shift. "Any time we're getting out-played in our own barn, it makes guys frustrated and angry. That brought out the fighting and what not."
The Warriors had 124 penalty minutes, including seven 10-minute misconducts, while the Pats were handed one 10-minute misconduct and had just 24 minutes in penalties.
Patrick D'Amico and Emil Sylvegard each scored once to round out Regina's offence.
Kendall McFaull and Tyler Bell scored for the Warriors (21-34-10), who are winless in four games.
Matt Hewitt stopped 35-of-37 shots for the win as Justin Paulic allowed seven goals on 33 shots in defeat.
"We know they're a good team off the rush," said Eberle. "We had enough chances again. Hewitt played well, but we really have to bear down on our chances. It seems to be that whenever we don't they come back and get one."
The Pats finished 4 for 9 on the power play while the Warriors were 1 for 2.
The Kootenay Ice defeated the Medicine Hat Tigers 4-2 on Friday, which means both Regina and Moose Jaw have been eliminated from WHL post-season play.
Elsewhere in the WHL, it was: Brandon 4, Prince Albert 2; Kootenay 4, Medicine Hat 2; Red Deer 3, Swift Current 0; Kamloops 4, Vancouver 2; Everett 4, Portland 2; Kelowna 7, Lethbridge 1; Tri-City 5, Seattle 3 and Spokane 3, Victoria 2.
At Moose Jaw, Sask., Scheidl opened the scoring 10:29 into the first period, but Bell responded a little over a minute later for Moose Jaw.
Sylvegard scored late in the first to give Regina a 2-1 lead after 20 minutes of play and Stephenson and Rodewald both scored in the second period to increase the advantage for the Pats.
Burroughs made it 5-1 1:29 into the third period before McFaull finally responded for the Warriors at 7:31.
Klimchuk and D'Amico added a goal each in the final five minutes to secure a victory for Regina.
Wheat Kings 4 Raiders 2
At Prince Albert, Sask., Nick Buonassisi scored twice and Curtis Honey stopped 36-of-38 shots as Brandon (22-38-6) doubled up the Raiders (35-24-6) to end its six-game winless slide.
Ice 4 Tigers 2
At Cranbrook, B.C., Mackenzie Skapski stopped 35-of-37 shots and Levi Cable had a goal and an assist as Kootenay (33-30-2) defeated Medicine Hat (33-30-2), which has a one-point edge on the Ice for sixth in the Eastern Conference.
Rebels 3 Broncos 0
At Red Deer, Alta., Patrik Bartosak earned his fourth shutout of the season by making 52 saves and Turner Elson scored twice as the Rebels (36-24-6) blanked Swift Current (31-28-7), which had its three-game win streak snapped.
Blazers 4 Giants 2
At Kamloops, B.C., Brendan Ranford set a new team record by playing in his 342nd regular-season game for the Blazers (43-18-5). The 19-year-old capped off the night with a third period goal as his club downed Vancouver (18-46-2).
Silvertips 4 Winterhawks 2
At Everett, Wash., Kohl Bauml scored twice and Austin Lotz made 43 saves as the Silvertips (23-37-5) handed Portland (51-12-3), the WHL's top club, its third loss in a row.
Rockets 7 Hurricanes 1
At Kelowna, B.C., Tyrell Goulbourne scored four goals and Cody Fowlie chipped in with three assists as the Rockets (46-15-4) extended their win streak to four games by crushing Lethbridge (26-29-10).
Americans 5 Thunderbirds 3
Chiefs 3 Royals 2
At Victoria, Eric Williams turned away 37-of-39 shots and Blake Gal scored the winner midway through the second period as Spokane (39-24-2) slipped past the Royals (32-26-2) for its fifth win in a row.