Monday, Monday . . . can’t trust that day.
That ageless pop tune played true for the Bruins on the first Monday of October, the Black and Gold falling behind by four goals early in the second period and eventually fizzling out altogether in a 4-1 loss to the Senators at TD Garden.
Tim Stützle scored twice in the first period, followed in the second by Drake Batherson and Michael Amadio, pacing the Senators to a win that was gift-wrapped by a constant, wide array of mistakes by the stumbling Bruins (now with two goals in their last two games).
Rookie James Hagens scored his second career goal, cutting Ottawa’s lead to 4-1 early in the third and preventing a whitewash on home ice.
Ex-Bruins goalie Linus Ullmark held his old team scoreless through two periods, then yielded to backup Samuel Ersson to start the third.
The Bruins, backed by Jeremy Swayman’s 20 saves, fell to 2-2-0 for the season and the Senators improved to 2-0-0. The Bruins landed only 19 shots on net.
Coach Marco Sturm is expected to give the Bruins a day off on Tuesday, a brief respite ahead of the Mammoth visiting Causeway Street on Thursday night.
Will Thursday, Thursday be better than Monday, Monday?
The night turned sour early mainly because of the Bruins’ stumblebum power play that led to two Stützle goals only 1:43 apart — the first shorthanded and the second generated from a scoring attempt that began with the Bruins still working with the same power play.
The Bruins were at a 2-0 deficit by the 9:22 mark.
Stützle, 24, is in his seventh season and increased his career total to 151 goals in 449 games. The third pick in the 2020 draft, he added an assist and is ranked No. 1 in point production (413) for that year’s draft class.
Kevin Paul Dupont can be reached at kevin.dupont@globe.com.