By Matt Kalman, CBS Boston

BOSTON (CBS) — In the postseason, there are different adages about what makes a series.

Some say a series hasn’t started until the road team wins, some say it begins when both teams have won at least one game, and there are many other permutations you could utter to sound wise.

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Well, I have one that applies to the Bruins’ current Eastern Conference quarterfinals series against Toronto: The series doesn’t start until Phil Kessel scores a goal.

In the Maple Leafs’ 4-2 series-evening victory Saturday in Game 2, Kessel finally lit the lamp against his old team. Folks, we now have a series.

It was Kessel’s first career even-strength goal against the Bruins in 24 games. It also gave the Leafs their first two-goal lead of the series. And if their confidence about beating the Bruins wasn’t already surging with them already ahead 2-1 entering the third period, the Maple Leafs have to be overflowing with faith they can at least push this series pretty far, if not send the Bruins home after one round. Their leading scorer and best skill player finally got on the score sheet and solved his long-time nemesis and former franchise.

“He’s one of the best players in the league so it doesn’t surprise me at all to see him be successful and see him create out there,” Maple Leafs forward James van Riemsdyk said. “And he’s really good at creating offense for our team and he’s been a really complete player for us all year and he’ll continue to do that.”

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If “King Kong” came off Kessel’s back with that goal, then the Maple Leafs had an entire jungle of monkeys come of their rears with their first playoff since 2004. Now we have a series. Toronto coach Randy Carlyle changed out four of his players from his Game 1 lineup and three – Jake Gardiner, Ryan Hamilton and Matt Frattin – recorded assists in Game 2. Bruins coach Claude Julien was forced to replace the suspended Andrew Ference, but he also chose to replace Kaspars Daugavins with Rich Peverley in an ill-fated attempt to jump-start the third line.

The chess match will now continue in Toronto. Julien has to make sure his defensemen tighten their gaps and don’t let the Leafs’ offense continue to pour it on. More end-to-end rushes like the one from Frattin on the second of Joffrey Lupul’s two goals might make Julien’s last hairs fall out. Without the second change, everyone will have to be on their toes on the Bruins’ bench, especially if Carlyle continues to shuffle Kessel from line to line.

The Leafs will have to continue to mix and match to make life difficult on the Bruins. They might even consider more lineup changes. The Bruins might even get more than nine seconds of power-play time in a game.

Anyone that got too caught up in the Game 1 victory was just looking for an excuse to party. This figured to be a series when it started, and now the series has started.

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Matt Kalman covers the Bruins for and also contributes coverage to and several other media outlets. Follow him on Twitter @TheBruinsBlog.