BOSTON -- Auston Matthews' return to the Toronto Maple Leafs' lineup wasn't enough to lift the road team Saturday in Game 7 of its first-round Stanley Cup playoff series vs. the Boston Bruins.

The Maple Leafs fell 2-1 in overtime as the Bruins advanced to a second-round series that begins on Monday. It was the Maple Leafs' sixth consecutive defeat in a Game 7, and their fourth straight to Boston.

Matthews was a late addition for Toronto's lineup after being absent from the third period of Game 4 all the way through Game 6. He had been battling both an illness -- which he played through in Game 3 -- and an undisclosed injury. Toronto's top forward didn't want to delve into specifics directly after the loss, however.

"I'm not going to go into that tonight," Matthews said. "I think maybe in the next couple days. We'll just process this [first]. It was really hard to watch those two games [when I was out]. Just really proud of the guys to fight and battle back and give ourselves a chance."

Matthews said he didn't know until Saturday morning that he'd receive clearance from the Maple Leafs' medical staff to play, and said his team, ultimately, gave all it could to try to get past the Bruins one final time.

"They're always a tough opponent," Matthews said. "They're a well-put-together team. But I thought we were right there with them. Tonight was a tight game. It's tough, could have gone either way."

Matthews finished the night with one assist in 17:35 of ice time, as Toronto tried to pull off a rally from a 3-1 series deficit.

The two sides were deadlocked at 0-0 in Game 7 until midway through the third period, when William Nylander beat Bruins netminder Jeremy Swayman to give Toronto a 1-0 lead. Hampus Lindholm responded just 80 seconds later with an equalizer that would eventually take the game to overtime.

David Pastrnak needed less than two minutes in the extra frame to flummox Maple Leafs goaltender Ilya Samsonov and send Boston on to face Florida in the second round.

Samsonov, who had been replaced by Joseph Woll in the third period of Game 4 before the latter then backstopped Toronto to consecutive wins, was a surprise starter on Saturday. Woll was sensational in both outings, posting a .964 save percentage and a 0.86 goals-against average in the series, but he suffered an injury that kept him from Game 7.

"Obviously, we didn't practice yesterday, we traveled, and it wasn't any better, in fact it was a little bit worse yesterday," Toronto coach Sheldon Keefe said of the injury. "We had told Samsonov he had to stay ready last night, there was a chance that Joe wouldn't be able to go, but Joe was going to do everything he could to try to be ready. The medical team was going to continue to work with him to get him ready, and that's the process they went through this morning.

"It wasn't until this afternoon that it was determined that Joseph wouldn't be available."

Samsonov came through with his best outing of the playoffs in a 29-save performance, but that couldn't cover up for Toronto's continued inability to produce offense. The Leafs scored just 12 goals total in seven games, which was a hurdle that helped determine their fate.

Before Matthews was forced out due to injury, it was Nylander who missed the first three games of the series with what he confirmed was a migraine issue. Nylander said on Saturday that at times the headaches would be so intense he couldn't see. Nylander said the Leafs' doctors thought the symptoms might be concussion related and held him out until he felt better.

"The situation is very complicated. It's hard to explain what it is," Nylander said. "It's hard to play [through that]."

Nylander also defended Toronto's nucleus of players, which includes himself, Matthews and Mitch Marner. Combined they scored five goals and 10 points in the first-round series that once again ended in disappointment.

"Look, I don't think there's an issue with the core," Nylander said. "I think we were right there all series. We battled hard."

Keefe concurred.

"When teams play the Leafs, they set up the game for the Leafs to beat themselves," he said. "I thought we did that in Game 3 and 4, we beat ourselves. We've been trying to break through for a long time. Any answer [now] is going to fall on deaf ears, and I get that. The core isn't different, but the feeling around the team was different and played different. I thought we showed signs in this series of a team that could win."