The NHL has fined Utah Mammoth defenseman Sean Durzi $5,000 for headbutting Vegas Golden Knights defenseman Rasmus Andersson during the first period of Game 1 on Sunday. The incident occurred after a whistle near the Utah bench with 3:28 remaining in the opening frame.

Durzi was assessed only a minor penalty for roughing on the play, while Andersson and Utah center Brett Howden also received matching roughing minors. Rule 47.3, Section 6 of the NHL rulebook stipulates that a head-butt should result in a major penalty and a game misconduct.

The fine is the maximum allowable under the collective bargaining agreement. Durzi, 27, logged 15:04 of ice time and recorded an assist in the 4-2 loss, which marked Utah’s first playoff game in franchise history.

Game 1 featured a combined 82 hits and 16 penalty minutes, with several scrums and altercations throughout. The Golden Knights lead the best-of-seven series 1-0. Game 2 is scheduled at T-Mobile Arena, where Vegas holds a 7-7 all-time record in Game 2s on home ice.