Atlanta had come off a 7-1 rout by Tampa Bay but Pavelec pulled off several huge saves to send the Thrashers into the All-Star break in good form.
Antropov scored at 11:21 of the second period after Washington defenseman Jeff Schultz lost control of a bouncing puck.
The Vancouver Canucks rallied to beat the Nashville predators 2-1 as Lee Sweatt scored the winning goal with 7:29 left in his first NHL game.
Nashville captain Shea Weber opened the scoring 37 seconds into the third period, but Alexandre Burrows tied it midway through the period.
Boston headed into the break in first place in the Northeast Division as All-Star Tim Thomas stopped 34 shots.
Brad Marchand and Milan Lucic scored for the Bruins and Bryan Allen netted for Florida who had Tomas Vokoun making 33 saves.
Jarret Stoll scored the only shootout goal in the fourth round as the Los Angeles Kings beat the San Jose Sharks 3-2.
Jonathan Quick made 22 saves and stopped all four San Jose tries in the shootout, snapping the Pacific Division rival's four-game winning streak.
The Dallas Stars won 3-1 over the Edmonton Oilers as Brenden Morrow scored twice and Kari Lehtonen made 34 saves.
The Detroit Red Wings ended the New Jersey Devils' four-game winning streak with a 3-1 victory.
Valtteri Filppula scored 5:32 into the third period and Darren Helam and Johan Franzen also added goals. Brian Rolston scored for New Jersey.
David Moss had two power-play goals and added an assist for the Calgary Flames as they beat the St Louis Blues 4-1 for their fourth straight loss.
Flames defenseman Adam Pardy had his first goal of the season and Jarome Iginla had an empty-net goal.
The Phoenix Coyotes beat the Colorado Avalanche 5-2 as Ilya Bryzgalov made 29 saves and Eric Belanger scored twice.
Keith Yandle had a goal and an assist, Scott Upshall and Kyle Turris also scored and Lee Stempniak had two assists to help the Coyotes stretch their road winning streak to five games.
Matt Duchene and Ryan Stoa scored for Colorado and Craig Anderson made 25 saves.
The Carolina Hurricanes were 4-2 winners over the New York Islanders as Eric Staal scored goals in a 1:38 span in the second period and also had an assist.
Zach Boychuk and Brandon Sutter also scored and Cam Ward made 23 saves.
Michael Grabner and Andrew MacDonald scored for New York.