Victory with 4-0 last night means that Toronto has got Montreal down the bridge and now leads 3-1 in matches in the eighth series' best of seven.
The decision may come as early as the night before Friday, Swedish time, when the teams meet again.
William Nylander is in great shape and scored his fourth playoff goal in as many matches.
He is the third Toronto player in NHL history to succeed in such a playoff goal, according to the NHL.
The first goal of the match
The Swede's goal was the first of the match and it came one and a half minutes into the second period, after Nylander received a behind-the-back pass by Alex Galchenyuk in front of goal.
After the 25-year-old's redemptive goal, Toronto got two more pucks in the second period.
Alex Galchenyuk then finished himself by putting the 4-0 goal in an empty goal cage in the final minutes.
The winner of Toronto and Montreal will face Winnipeg in the quarter-final series, which on Tuesday beat Edmonton after 4-0 in matches.
3-2 in matches for Carolina
Nashville, with the Swedes Filip Forsberg, Calle Järnkrok, Viktor Arvidsson and Mattias Ekholm, had the chance to take the lead in the round of 16 against Carolina when the team met for the fifth time last night.
After being knocked out by Carolina in the first two playoff games, Nashville came back and managed to win the next two games.
Before tonight's match, it was thus 2-2, and Nashville did not want to settle for that.
The Swedish team took the lead with both 1-0 and 2-1.
But Carolina, with Jepser Fast on the ice, equalized in the third period and then managed to score a winning goal just two minutes into extra time.
Carolina, who won the Central Division in the regular season, thus leads 3-2 in matches.
The teams meet again the night before Friday, Swedish time.