BOSTON — To be the best, you have to beat the best, and the Toronto Maple Leafs’ top line was unable to get much going offensively against the NHL’s best line in a 5-1 loss to open their first-round Stanley Cup playoff series against the Boston Bruins at TD Garden.

Boston’s top line of Brad Marchand, Patrice Bergeron and David Pastrnak dominated opponents throughout the season — all three scored 30-plus goals and as a line ranked third in puck possession at 5-on-5 — and their excellent production at both ends of the ice proved decisive in Thursday’s Game 1.

Boston’s top trio neutralized one of the most skilled lines in the NHL, one that combined to score 69 goals and help the Leafs rank third in goals scored.

“They’re a 200-foot line. They’re good,” Leafs defenseman Morgan Rielly said of Boston’s top line. “They’ve got lots of speed, lots of skill. They’re responsible, so they did a good job (Thursday night).”

Here’s a look at how the Bruins fared when Bergeron was on the ice against the Leafs’ first line of Zach Hyman, Auston Matthews and William Nylander at 5-on-5. The B’s had a better than 2-to-1 edge against all three:

Hyman did score a goal in the first period, but it didn’t come against the Bergeron line. Matthews tallied just three shots on goal. Nylander tallied only one. Both of them were held scoreless, and Hyman had only one more shot on goal after his first-period tally.

Here’s a look at how tilted the ice was in Boston’s favor when the Bergeron line was on the ice during 5-on-5 play against all opponents Thursday. The Bruins had better than a 3-to-1 edge in shot attempts, and this advantage pinned the Leafs in their own end and wore them down as the game went on. (shot attempts in the chart below are a team total, not individual)

Marchand scored a goal and added an assist, Bergeron tallied one assist and Pastrnak scored and chipped in two helpers. They combined for 13 shots on goal.

The Bruins were one of the best 5-on-5 teams in the league this season. They ranked second in Corsi For percentage at 5-on-5, accounting for 53.2 percent of all shot attempts. The B’s tallied 64 percent (54 to 30) of the 5-on-5 shot attempts in Game 1.

The Leafs must find a way to get their top line, and Matthews in particular, better looks at the net in Game 2. It will be easier for them to evade the Bergeron line in Toronto because the home team has the last line change, but the Leafs must win a game in Boston to survive this series.

The Bruins’ top line won the first test, but they understand the Leafs’ top trio is too talented to take lightly at any point in this series.

“It’s really tough. They’re a really tough line to play against,” Marchand said. “They move fast and make a lot of plays, especially one-on-one down low. We had our hands full with them (Thursday night), and if we play against them next game we’re going to have our hands full again.”

Thumbnail photo via Bob DeChiara/USA TODAY Sports