The Ottawa Senators have emerged as one of the NHL's top postseason contenders over the past couple of months, but that playoff run won't last long if they continue to blow third-period leads.

The Senators try to snap a three-game losing streak when they open a home-and-home series with the Toronto Maple Leafs on Thursday at Scotiabank Place.

Ottawa (38-23-6) has the third-most points in the Eastern Conference with 82, thanks in large part to a 21-4-3 stretch from Dec. 23-Feb. 28. The Senators, however, have rattled off three straight defeats since then, all due to late-game collapses.

Ottawa led 4-1 midway through the third period Tuesday before allowing three goals in a three-minute span en route to a 5-4 shootout loss to the Pittsburgh Penguins. The Senators held a 3-1 third-period lead versus Chicago on Sunday before losing 4-3 in a shootout, and allowed three goals in the final 17 minutes Friday in a 4-2 defeat to Atlanta.

"We needed a big save or a big goal, or something, but it seems like the other team's been making the big plays later on in the game," said Senators goaltender Ray Emery, who made 23 saves Tuesday.

Despite being in goal for two of those losses, Emery will start versus the Maple Leafs (32-26-9). He is 3-1-1 with a 2.83 goals-against average in seven career games against them.

Emery has allowed four or more goals in three of his last four starts after doing so just five times in his first 39 appearances of the season.

He'll look for a better performance as the Senators try to avoid losing four straight for the first time since a five-game skid from Oct. 28-Nov. 8.

It would be hard to blame Ottawa leading scorer Dany Heatley for this slide, with 10 goals and nine assists during his current 12-game point streak. He has 19 goals and 36 points in 22 career games versus the Maple Leafs - his most goals and second-most points versus any opponent.

Heatley may further benefit from the return of linemate Jason Spezza. The Senators' third-leading scorer sat out Tuesday's loss with a sore back and didn't practice Wednesday, but is hoping to be back in the lineup against Toronto.

"It's spasms," Spezza told the team's official Web site Wednesday morning. "It's getting better and I'm hoping (to return Thursday). It's probably a game-time decision, a day-to-day thing. My back has been feeling great this season. This is totally different from (the back injury) last year."

Spezza has seven goals and 12 assists during his own 11-game point streak. The center has seven points in his last three games against the Leafs, and his 28 points in 20 career meetings is tied for his most versus any opponent.

Spezza has helped the Senators go 4-1-1 against Toronto this season and hold a 11-2-1 edge in the last 14 meetings between the provincial rivals.

The Leafs, though, did win the last matchup 3-2 in a shootout on Feb. 3, and are coming off a 3-0 victory over the Washington Capitals on Tuesday.

Toronto's third win in eight games moved the team into a tie with Carolina for the eighth and final playoff spot in the tightly contested Eastern Conference. Just six points separate eighth and 13th place.

"We'll keep working hard and putting pucks to the net," said Leafs goaltender Andrew Raycroft, who made 24 saves for his second shutout of the season. "We're playing well right now.

"We just need to continue to play solid defense and stay in these games. We're starting to win the close games now. We all have a lot of confidence in the tight ones."

Darcy Tucker and Yanic Perreault each recorded their 20th goal of the season Tuesday while Alexei Ponikarovsky scored his 18th. It was Tucker's first goal in his second game back after missing more than two months with a broken left foot, and Perreault's first since rejoining the Leafs in a deadline trade.