Logan Cooley had a goal and an assist, and Nick Schmaltz had two assists for the Mammoth (6-2-0), who have won three in a row and will host the Oilers on Saturday. Karel Vejmelka made 21 saves.
Leon Draisaitl and Shakir Mukhamadullin scored for the Oilers (5-1-1), who won their previous five and were the last team in the NHL without a regulation loss. Devon Levi made 20 saves.
Barrett Hayton put Utah ahead 1-0 on the power play at 10:38 of the first period, cleaning up the rebound in close on a point-blank shot from Kailer Yamamoto.
Keller made it 2-0 on the power play at 11:57 of the second period, taking a through-the-legs pass by Cooley from the slot, and snapping it short side past Levi’s glove.
Draisaitl cut the lead to 2-1 at 13:54, on a give-and-go from Connor McDavid that he slid through Vejmelka’s legs.
The assist extended McDavid’s season-long point streak to all seven games (four goals, 14 assists).
The Mammoth went ahead 3-1 just 23 seconds later at 14:17, when Cooley drove to the crease to reach a backhand pass from Vincent Trocheck, and lift it past Levi’s glove.
Mukhamadullin closed it to 3-2 at 1:40 of the third period when his wrist shot from the point bounced in off the skate of Mammoth defenseman Andrew Peeke. It was his first goal with the Oilers after being traded from the San Jose Sharks on July 1.
Keller added an empty-net goal with 28 seconds remaining.
