CALGARY, Alberta -- Center Mika Zibanejad scored a natural hat-trick in the third period to lift the Ottawa Senators to a come-from-behind 6-4 win over the Calgary Flames on Thursday.

The Flames led 4-2 after 40 minutes.

It was Zibanejad's first three-goal game in 262 NHL games. Center Zack Smith, left-winger Nick Paul and Jean-Gabriel Pageau also scored the Senators (30-27-6), who have won five of their past six games.

Gaudreau, center Sean Monahan and center Joe Colborne scored for the Flames (26-31-4), who have lost four straight.

Gaudreau and Monahan were playing their first game without their linemate for the past two seasons, Jiri Hudler, who was traded to the Florida Panthers earlier in the day for a pair of draft picks.

Zibanejad's hat-trick came in a span of 2:38. His sharp angle shot got under the crossbar to cut the Flames lead to 4-3 at 6:13 of the third period. He then converted a long rebound at 7:59 to tie the game. Then, he scored again while on one knee at 8:48, chipping a shot over Flames goaltender Joni Ortio.

Ottawa is six points behind the Pittsburgh Penguins in the hunt for the second wild-card berth in the Eastern Conference. Calgary is 12 points back of the Colorado Avalanche for the second Western Conference playoff wild card.

The Flames got to Senators goalie Craig Anderson with two quick goals in the first period. Colborne beat him through the pads on the power play at 6:24 and Monahan put a wrist shot by him inside the glove-side post at 7:06.

Defenseman Erik Karlsson's point shot deflected off Smith's leg and past Ortio at 18:21 to get Ottawa on the scoresheet.

Each team's power play took advantage of the other's awful penalty killing in the first period. The Flames are dead last in penalty killing percentage in the league in 30th spot and the Senators are 29th.

Gaudreau made it 3-1 in the second with a burst of speed down the left wing and a wrister over Anderson's glove into the top corner at 10:23.

Hard work by right winger Curtis Lazar behind the Calgary net created the Senators' second goal. He outworked the Flames defense, dragged the puck out to the corner and fed Paul, who blasted a long shot past Ortio at 14:24.

Gaudreau got that back with a wrist shot inside the post from high in the right faceoff circle with 22.5 seconds left in the second.

NOTES: Senators RW Chris Neil signed a one year, $1.5 million contract extension Saturday that will keep him in Ottawa for a 15th season. Neil played his 956 NHL game Saturday -- all with the Senators. ... Flames D Kris Russell sat out for the seventh straight game with a lower body injury. It's been widely speculated the past week that the 28-year-old pending unrestricted free agent will be traded prior to Monday's deadline after being unable to come to terms on a new contract. ... Senators healthy scratches were D Patrick Wiercioch and LW Shane Prince. ... The Flames did not have any scratches after RW Jiri Hudler was traded to Florida earlier Saturday, leaving them short a man. RW Josh Jooris took his spot in the lineup after he was the odd man out for Thursday's overtime loss to the New York Islanders.