Evander Kane, Zach Hyman and Ryan Nugent-Hopkins each scored goals to give the Edmonton Oilers a 3-0 lead over the visiting Calgary Flames after the first period of Game 4 on Tuesday.
Nugent-Hopkins opened the scoring 21 seconds into the frame.
Hyman converted his goal on a man-advantage at the 9:53 mark with assists from Connor McDavid and Leon Draisaitl.
Kane capped off the scoring with just over one minute left in the period on an assist by Draisaitl.
Mike Smith got the start in net for the Oilers, while the Flames countered with Jacob Markstrom.
Calgary outshot the Oilers 14-9.
The Oilers lead the best-of-seven second-round series 2-1.