BUFFALO, N.Y. -- Newly acquired center Ryan O'Reilly scored twice on Toronto's first two shots on net and added an empty-net goal in the Maple Leafs' 6-3 victory over the Buffalo Sabres on Tuesday night.

Playing his third game in four nights since being traded to Toronto by the St. Louis Blues, O'Reilly scored 37 seconds apart in an opening period the Maple Leafs led 4-0 on goals scored in a span of 8:18. O'Reilly added two assists and sealed the win with the first five-point outing of his career by scoring into an empty net with 1:10 remaining -- and after the Sabres scored three times to cut Toronto's lead to 5-3.

"Seeing the hats on the ice in an away arena is pretty cool," O'Reilly said. "Kudos to our fans."

It was his fourth career hat trick and came against one of this former teams.

"Oh yeah, it feels a little better doing it in this building," O'Reilly said.

O'Reilly's new linemates got in on the fun, with captain John Tavares scoring and adding three assists, and Mitchell Marner setting up five goals.

"That line, our team in general, our team game in that first period, it was as dominant as we've been all season long," Toronto coach Sheldon Keefe said. "It was tremendous to see."

Michael Bunting and William Nylander also scored in a game played before a large contingent of "Go, Leafs! Go!" -- chanting, blue-and-white clad fans making the trip across the border.

Ilya Samsonov, who didn't face his first shot until halfway through the first period, finished with 29 saves. He stopped the first 22 shots he faced before getting beaten three times in the final 14:48.

Alex Tuch, with the 100th goal of his career, Jack Quinn and Jeff Skinner scored for Buffalo in a game the Sabres trailed 5-0 through two periods.

Buffalo's Ukko-Pekka Luukkonen allowed four goals on 10 shots before being yanked after getting beaten on the short side by Bunting 12:09 in. Struggling in his bid to win a three-way goalie competition, Luukkonen has allowed 19 goals in dropping to 1-3-1 in his last five starts. He was replaced by Craig Anderson, who finished allowing one goal on 18 shots.

O'Reilly's offensive outburst came in a homecoming for the two-way center, who spent two seasons playing for the Sabres before being traded to St. Louis in July 2018.

The playoff MVP for the 2019 Stanley Cup-winning Blues opened the scoring 3:51 in by snapping in Marner's centering pass into the open left side of the net. Set up by Marner again, O'Reilly broke in alone and backhanded a shot, beating Luukkonen on the short side 37 seconds later.

Tavares then made it 3-0 at 7:14 by converting a loose puck after a shot by Marner from the right circle was blocked in front.

In earning their 78th point, the Maple Leafs (35-15-8) matched a franchise record for points through their first 58 games of a season and set last year, when they were 37-16-5. They now have four points in the three games that O'Reilly has played in.

"I think anyone that plays with him or knows him, he's a hell of a guy, he works extremely hard," Marner said of O'Reilly. "He wants to come in here and help his team win games."

The Associated Press contributed to this report.