Rask won it when he skated in on a 2-on-1 and shot short side from the left circle on Ryan Miller.
Kirill Kaprizov had two assists, and Cam Talbot made 19 saves for Minnesota (35-14-5), which also won 4-3 in overtime here Friday and is 4-0-2 in its past six games.
The Wild remained one point behind the Colorado Avalanche, who defeated the Los Angeles Kings 3-2 on Saturday and have one game in hand, for second place in the division. Minnesota, Colorado, the first-place Vegas Golden Knights and fourth-place St. Louis Blues have clinched the division's Stanley Cup Playoff berths.
"We took care of business this weekend, gave ourselves a chance at home ice in the playoffs, and then see where the chips fall with Colorado's games moving forward," Wild forward Nick Bonino said. "But we'll just try to handle what we can and see if we have home ice, that's something we'd really like."
Max Comtois and Rickard Rakell each had a goal and an assist for Anaheim (17-30-9). Miller made 21 saves in the final game of 18-season NHL career.
"It was a fun game," Miller said. "Happy with the way we settled back in the third period. It's good to compete to the end.
"I want to say goodbye, and I think it's going to help moving forward for sure. It was a lot of fun."