Watch: Stars' Tyler Seguin delivers head shot on Golden Knights' Shea Theodore

An already-intense first-round Stanley Cup Playoff series between the Dallas Stars and Vegas Golden Knights became more so near the midway point of Game 5.

In the second period of a tied game 2-2, Stars forward Tyler Seguin delivered a massive hit on Golden Knights defenseman Shea Theodore, leading to a little get-together between the two sides.

Initially, referees assessed Seguin with a major penalty for a hit to the head, but it was downgraded to a minor following review.

With their first-round playoff series tied at 2-2, Game 5 has been fast and furious. The Stars and Golden Knights traded two goals each in a back-and-forth first period, and the intensity continued to rise in the second.

After some more rough stuff near the end of the period, referees reversed another major. At 15:19 of the second period, Golden Knights defenseman Alex Pietrangelo appeared to elbow Seguin, earning him a five-minute penalty. Still, replays showed the Dallas forward embellishing a backhand, and officials agreed, downgrading it to two minutes.

Nevertheless, the Stars capitalized on the power play when winger Jason Robertson lit the lamp at 16:32, helping Dallas take a one-goal advantage into the intermission.