BOSTON — Pavel Zacha scored 2:49 into overtime, and the Boston Bruins beat the Philadelphia Flyers 4-3 on Saturday for their fourth straight victory.

Boston’s Brad Marchand tied it with 5:22 left in regulation. Trent Frederic had the other two goals for Boston, which is 7-2 since interim coach Joe Sacco took over for fired coach Jim Montgomery.

Zacha scored the winner after Boston goalie Jeremy Swayman stopped Joel Farabee’s breakaway seconds earlier.

Rookie Matvei Michkov scored two first-period goals for Philadelphia in its second straight loss. Cam York also scored, and Travis Sanheim had two assists.

Coming off a frustrating loss against Florida when they gave up a season-high seven goals, the Flyers blew a third-period lead for the second game in a row.

Michkov scored a power-play goal at 7:24 when he one-timed a shot from the right circle off a short tip pass from Sean Couturier. His second came on a redirected shot at the edge of the crease.

TAKEAWAYS

FLYERS: Leading all rookies in scoring coming into the day with nine goals and 22 points, Michkov had three assists in his last game on Thursday.

BRUINS: Sacco used star winger David Pastrnak on the top line with Brad Marchand for the second straight game and the first two times this season after Marchand scored two goals in Boston’s last game.

KEY MOMENT

Marchand hustled to a puck deep in the offensive zone, skated around Tyson Foerster and slid the puck between Aleksei Kolosov’s pads for the tying goal.

KEY STAT

The Bruins won the season series, 2-1.