BUFFALO, N.Y. - A week ago, William Karlsson wasn't sure he made the Anaheim Ducks' roster until the centre boarded the team flight for a season-opening four-game eastern road swing.

On Monday afternoon, the rookie 21-year-old centre was celebrating his first two NHL goals following a one-sided 5-1 win over the winless Buffalo Sabres.

"I had a goal to make the team, but I was ready to go back to Norfolk," Karlsson said, referring to the Ducks' Virginia-based AHL affiliate. "But now I'm here. And now my next focus is the next game."

Karlsson has certainly earned his opportunity filling the third-line centre role in place of injured forwards Dany Heatley (groin) and Kyle Palmieri (ankle). He put the Ducks up 2-0 at 8:15 of the second period by snapping a shot in from the slot. Karlsson then made it 4-0 early in the third period, when he batted in his own rebound.

Coach Bruce Boudreau held out Karlsson in the Ducks' opener at Pittsburgh, before giving him a shot in a 3-2 win at Detroit on Saturday.

"We put him in, and it was, 'Not bad. Let's see what he's got again,'" Boudreau said. "And tonight, I thought he was our best player."

Ryan Kesler scored on a third-period penalty shot and Corey Perry and Matt Beleskey had a goal each in a game Anaheim outshot the Sabres 44-12.

The Ducks (2-1) were so dominant — and Sabres so inept — that Anaheim was outshooting Buffalo 40-10 when Kessler beat goalie Michal Neuvirth with a low shot inside the left post with 7:35 remaining.

Tyler Ennis scored the Sabres' lone goal, spoiling Frederik Anderson's first career-shutout bid at the 6:36 mark of the third period.

"It was like an NHL team playing against a Pee Wee team. They dominated us from start to finish," Sabres coach Ted Nolan said. "We weren't strong enough, not committed enough, not smart enough. No desperation."

Neuvirth held his own by stopping 39 shots in making his first start. The trouble was, the Sabres provided little offensive support after being outshot 29-7 through 40 minutes.

The Sabres hardly look improved in coming off a last-place finish in which they scored an NHL post-expansion-era-low 150 goals, and lost a franchise-worst 51 games. Before last year, Buffalo had never opened a season 0-3. Now the Sabres have done it in consecutive years.

Following a 6-2 loss at Chicago, Buffalo has been outscored by a combined 14-4 and outshot 131-57.

"We need to be mad and get angry," Ennis said, looking ahead to Buffalo's game at Carolina on Tuesday. "We need to play really hard tomorrow and we will."

The only downside to the Ducks' victory was forward Patrick Maroon not returning after hurting his left leg 11 minutes into the second period. Maroon was driving up the right wing, when his left knee was clipped by Sabres defenceman Josh Gorges' hip check near the boards. Maroon lay on the ice for several minutes and required help to be escorted to the locker room.

Maroon was spotted leaving the Ducks' locker room with his left leg immobilized.

Boudreau said it was too early to determine the severity of the injury, but added there was no chance Maroon will play at Philadelphia on Tuesday.

Perry opened the scoring with a power-play goal at 15:30 of the first period. Anaheim then sealed the victory in the first four minutes of the third, when Beleskey and Karlsson scored 18 seconds apart to make it 4-0.

The crowd was so unhappy that it cheered when Cody McCormick shot the puck the length of the ice and into an open Anaheim net after the whistle blew following a delayed penalty against Buffalo late in the first period.

NOTES: Before the game, NHL Commissioner Gary Bettman was in Buffalo to announce the Sabres had been selected to host the 2016 draft. ... Sabres LW Marcus Foligno did not play after getting, what coach Ted Nolan called, "banged up" in a 6-2 loss at Chicago on Saturday. Flynn made his season debut in Foligno's place. ... Ducks G Andersen matched a career best by winning six in a row dating to last season.