The Bruins opened December by doing something they got used to in November when they beat the Leafs, 4-1, at TD Garden Saturday. The B’s are now 4-0-0 against the Leafs this season and lead the Northeast division by three points.

David Krejci opened the scoring for the Bruins at 4:20 of the second period, but Mikhail Grabovski answered back 48 seconds later to tie it. Chris Kelly then scored his 10th goal of the season to make it 2-1, with Johnny Boychuk adding to the Bruins’ lead with a bomb past Toronto goaltender James Reimer in the third period. Nathan Horton scored on a wrist shot from the top of the circle to make it 4-1.

Picking up the victory for the Bruins was Tuukka Rask, who improved to 4-3-1 on the season. He made 21 stops Saturday.

The Bruins have a busy week ahead of them. They’ll face the Penguins in Pittsburgh on Monday, the Jets in Winnepeg on Tuesday, the Panthers at home on Thursday and the Blue Jackets in Columbus on Saturday.

WHAT WENT RIGHT FOR THE BRUINS

- Count me and everyone else in the world among those surprised that Kelly has scored 10 goals through 24 games. The third-line center took a long pass from the bottom of the circle across to Kelly, who beat Reimer to break the 1-1 tie in the second period.

Kelly’s career-high in goals was 15, which he registered in both the 2006-07 and 2009-10 seasons in Ottawa. It’s safe to say he’ll be surpassing the mark this season. Add to the equation that the alternate captain will be an unrestricted free agent at the end of the season, and you’ve got a player exceeding expectations at the same time.

- He didn’t face an insane amount pressure early on, but Rask made timely saves in final two periods and had his latest strong outing, further proving that he isn’t average goaltender he was a season ago. Rask has now allowed one in two of his last three starts, as he also held the Blue Jackets to one goal on Nov. 17.

The Bruins likely went with Rask Saturday so they could play Tim Thomas Monday against the Penguins and go back to Rask the next night against the Jets, and the decision has paid off so far.

- Joe Corvo received his first career major penalty when he fought Joey Crabb in the third period. The puck-moving defenseman had gotten in a tussle with Boris Valabik (who ended up being a throw-in in last season’s trade with the Thrashers that sent Rich Peverley to Boston) in 2008, but did not receive a major.

- Phil Kessel was a minus-4 for the Maple Leafs over this week’s home-and-home against the Bruins. If that doesn’t say “mission accomplished” for the B’s gameplanning, nothing does. Zdeno Chara put a big hit on the Toronto winger in the first period, and that kept the NHL’s leading goal-scorer quiet for essentially the remainder of the opening 20 minutes. Kessel finished the night with five shots on goal, but he finished the home-and-home without a goal.

- Whatever kind of slump Krejci was in prior to this week, it’s definitely over now. The recently re-signed center has four points (2 G, 3 A) over his last two games.

- Saturday night marked the Bruins’ 100th consecutive sellout. Fun note: the the streak began two seasons ago against the Maple Leafs.

WHAT WENT WRONG FOR THE BRUINS

- The B’s have been known to score goals in bunches this season, but on Satruday, rather than scoring again soon after scoring, the B’s allowed a goal in the “vulnerable minute” when The Bruins last allowed a goal within a minute of scoring last Friday against the Red Wings. Pavel Datsyuk scored on Rask 35 seconds after Daniel Paille beat Jimmy Howard in the second period.

- Tyler Seguin has one goal over his last nine games. He also has two assists in that span, but it’s a far cry from the pace at which he was producing earlier in the season. In the four games prior to the aforementioned stretch, Seguin had an incredible seven goals, including a hat trick on Nov. 5 against the Leafs.

Seguin and Brad Marchand had a great scoring chance in the second period on a 2-on-1 Saturday, but the playas doomed by one too many passes. The 19-year-old was on the ice for Boychuk’s goal, increasing his league-best plus-minus to plus-20. Seguin has still been a point-per-game player thus far, leading the B’s with 24 points (12 G, 12 A) through 24 games.