If the Cannons were to avoid their first losing streak of the season - and become the first MLL team to clinch a playoff berth - the sloppiness had to end.

But outside of a resurgent second quarter, the Cannons couldn’t find a rhythm and suffered their second straight loss, 16-12, before 7,503 at Harvard Stadium.

“This is where we want to play well for the fans, first and foremost, and we didn’t do it tonight,’’ said middie Matt Poskay, who led the Cannons (6-3) with four goals. “We played for one quarter.’’

The Nationals (5-4) scored the first four goals of the third quarter to take control, 12-9. Poskay followed that run with a pair of goals, and Hamilton’s Donny Moss answered on a Brodie Merrill feed to give Hamilton a 13-11 lead with a quarter to play.

The Cannons’ Kevin Buchanan (three goals) got the fourth quarter off to a good start, scoring 24 seconds in. It proved to be the Cannons’ last goal of the game, as the first-quarter sloppiness returned in full force, the slide capped by an empty-netter from Brett Bucktooth (game-high five goals).

“[It was the] turnovers, bottom line,’’ said Cannons coach Bill Daye. “Simple things, throwing and catching, that at this level we take for granted. Tonight it shot us in the foot.’’

Despite the weak play by the field players, the Cannons left the stadium with one big takeaway: the play of Burke, who turned away 16 shots in another strong effort.

The Cannons had an early chance when Merrill was flagged near the Cannons’ crease at 4:19 of the first, putting Boston up a man. But the Cannons squandered the power play as an errant pass landed out of bounds.

On the ensuing possession, Hamilton’s Kevin Crowley pushed through the Cannons’ defense before losing the ball behind the net. Bucktooth recovered, wrapping his stick around the pipe and past an out-of-position Burke at 5:17 for the game’s first score.

Bucktooth found net again nearly two minutes later, deftly redirecting a bullet from Joe Walters on Burke’s doorstep. Jeremy Boltus put in the Nationals’ third with 10 seconds left in the frame.

The Cannons were noticeably sharper in the second quarter. Paul Rabil fired an early shot that seemed to go in - to the crowd’s applause - but the ball trickled out from under Scott Rodgers (20 saves) after a few seconds.

The Cannons kept the heat on, though, and Buchanan gave Boston its first tally a minute later. The score ignited a five-goal run by the Cannons.

The Nationals disrupted this momentum on a Cody Jamieson score with just more than five minutes to play, and from there the teams traded shots, with Boston taking a 9-8 lead into halftime.