LAKE BUENA VISTA, Fla. -- For the second time in six games of this Eastern Conference semifinal series, the Boston Celtics failed to deliver a knockout blow to the Toronto Raptors.

But after Toronto's heart-stopping, 125-122 double-overtime victory over Boston in Game 6 on Wednesday night, Celtics guard Kemba Walker remained confident he and his teammates have what it takes to finally close out the defending champions in Game 7 on Friday night.

"Why wouldn't I be?" Walker asked. "We're great players. We are really competitive.

"That was a hard-fought game right there. We could have given up. We didn't. We made plays throughout the whole game, two overtimes.

"I'm confident. We have a good group of guys and we love playing basketball with each other and we love making each other better. I know we'll respond. We're going to come out and play hard again."

The Celtics -- or the Raptors, for that matter -- couldn't have played harder than they did in this one. Bodies were flying everywhere, and both teams hardly made a single substitution down the stretch. In fact, the Celtics didn't make a single one in the fourth quarter or either overtime.

But, in the end, it was Toronto that managed to make just enough plays to survive its second extinction event in this series -- the first coming when Walker made an insane pass to Daniel Theis for a dunk with .5 seconds left in Game 3, only for Raptors forward OG Anunoby to drill a buzzer-beating 3-pointer right after.

The difference between that game and this one, however, is that Walker was virtually nonexistent. After having his way with the Raptors for the vast majority of this series heading into Game 6, Toronto coach Nick Nurse utilized a box-and-one to limit Walker to just three shots -- all misses -- in the first half.

Walker finished with just five points on 2-for-11 shooting in 52 minutes Wednesday night, as he was unable to make the kinds of plays that he made seem routine both against the Philadelphia 76ers in the first round and then against the Raptors for much of this series.

"The second half, I just couldn't really find a rhythm," Walker said. "I thought I had a few good looks, but it just wasn't enough to help my teammates out tonight. Just a bad offensive night for me, terrible offensive night for me."

Walker's teammates did their best to pick him up, but they still played their part in Boston's loss. Jayson Tatum finished with an eye-popping stat line -- 29 points, 14 rebounds and 9 assists -- but made a critical turnover late in the second overtime, driving when it appeared he had an open shot, leading to a steal that turned into a Norman Powell and-1 layup at the other end.

Jaylen Brown, on the other hand, finished with 31 points -- but went 11-for-30 from the field. And while Marcus Smart had a terrific game, finishing with 23 points, 11 rebounds and 10 assists, it was his foul on Powell with 38.8 seconds left that helped give Toronto the distance it needed to edge Boston for the win.

After the game, Smart got into it with the Raptors after getting tangled up with center Marc Gasol on the final play, causing both teams to come together before eventually separating.

Apparently, 58 minutes on the court together Wednesday night wasn't quite enough for everyone.

"A lot of emotions and things like that swirling," Brown said, when asked about what happened after the game. "I ain't gonna really speak on it too much, but it's a lot of emotions and it's an intense series, so things like that tend to happen. A lot of testosterone, etc.

"We gotta be ready to fight. That's a respectable organization, I expect them to act accordingly, etc. Things seemed to get out of hand at times, from coaching staffs, etc. Let's keep it under control; let's keep playing basketball; let's be ready to fight."

If Game 6 was any indication, there will be a pair of teams ready to fight for another 48 minutes -- and then some -- to see who will advance to the Eastern Conference finals to face the Miami Heat next week.

"They're a tough group, man," Walker said. "They make big plays. They make big shots. They're the defending champs. We're going to get their best every single time. So, like I said, we just have to be better. We have to find a way."