Kostitsyn had a goal and an assist and Rinne tied Nashville's single-season record with his 36th victory as the Predators beat the Florida Panthers 3-1 on Saturday night.
Rinne stopped 39 shots as he continued his hot streak and tied Tomas
Vokoun's franchise record of 36 wins 2005-06. Rinne, who leads the League in victories, has given up two goals or less in each of his last eight starts.
"He's our backstop," center David Legwand said. "He's our best defender out there. That's huge for us. We're excited to have him."
Rinne's performance helped the Predators improve to 5-1-1 in their last seven games despite being outshot 40-23.
"I don't say this in a sarcastic or negative way at all, but goaltending was the difference tonight," Florida coach Kevin Dineen said. "And it had nothing to do with what went on at our end. Pekka Rinne earns his keep every time he goes out. He had a heck of a game. You get a quick look at some of the chances that we had and he had to come up extremely big for them, which he seems to do every single game. We put a lot of pressure on him and unfortunately we weren't able to get any by him.”
Kostitsyn's goal was the 100th of his career and his first in two games with the Predators since being acquired from Montreal.
Kostitsyn opened the scoring at 11:35 of the first period off a 2-on-2 rush. Kostitsyn crossed the blue line on the left side before skating all the way across the ice. He beat Scott Clemmensen with a wrist shot from outside the right faceoff dot that went in off the post on the far side.
"He can do that," said defenseman Hal Gill, who played with Kostitsyn in Montreal before the two were reunited in Nashville. "Every once in a while he does amazing things and it blows you away. He's strong, he's big, he can shoot the puck -- and when he unleashes it, it's tough for the goalies to stop.
"He has game-breaker ability. He can go down and just a simple shot from the side, he can score. And that can change a game."
The assists on the goal went to Paul Gaustad and Gill, the other two veterans acquired by the Predators before or at the trading deadline.
"It was nice, huh?" Gill said. "It's nice to have everyone chipping in. Things weren't really going our way early on and to get a goal like that kind of lifted us up a little bit.”
Mike Fisher and Legwand also scored for the Predators, who had been off since losing 4-3 at Carolina on Tuesday.
The Predators are in fifth place in the Western Conference and extended their lead over sixth-place Chicago to six points.
"We can't get comfortable," Fisher said. "We do have a cushion, but we want to keep moving up. We had some additions here recently, and we want to make sure they're feeling comfortable and playing well for us and improving as a team. We want to be going into the playoffs playing our best hockey and we can play much better than we did tonight."
Wojtek Wolski scored his second goal in five games with Florida since being acquired last Saturday in a trade with the New York Rangers.
Clemmensen made 20 saves for Florida, which failed to extend its lead in the Southeast Division. The Panthers lead Winnipeg by two points with two games in hand and have a three-point lead over Washington with both teams having 18 games remaining. Tampa Bay is four points behind but has only 17 games left.
The Panthers, who played their third consecutive game without scoring leader Kris Versteeg (lower body) lost for the sixth time in their last nine outings (3-5-1). Things don't get easier on Sunday as the Panthers face an Ottawa team that has beaten them nine times in a row.
"The effort was there," defenseman Jason Garrison said. "We did a good job of putting pucks on net, crashing the net. Their goalie played really well. They made the most of our mistakes.
"We've just got to get some rest here and let this one go and put a really good effort in tomorrow and come up with two points."
Rinne was particularly impressive in the first period when he helped the Predators take a 1-0 lead to the locker room despite Florida outshooting Nashville 15-6. Rinne also got a break when Tomas Fleischmann hit the post with a wrist shot.
Early in the third period, Rinne stopped Fleischmann's wrist shot on a 2-on-1 when the score was 2-1.
Rinne's heroics were nothing surprising for Jerred Smithson, who was acquired by the Panthers from Nashville in a trade on Feb. 24 and was facing his former team for the first time.
Asked what's the key to beating Rinne, Smithson replied: "I've been shooting on him for so long and I don't know how to beat him. He's just good, he's competitive, they rely on him and they play well in front of him. He'll make the first few saves and they're pretty good at clearing out after that. We'll learn from it and move on. We've got a huge game tomorrow. It's a must-have."
Kostitsyn's assist came on Legwand's breakaway goal at 7:02 of the third period. The Predators took advantage of a bad line change by the Panthers, and Legwand beat Clemmensen with a deke between the legs.
Fisher scored 28 seconds into the second period after Martin Erat won a battle with Mike Weaver behind the Florida net. Erat fed a backhand pass to Fisher, who one-timed it past Clemmensen's glove.
It was the fourth time in the last five games the Panthers fell behind 2-0. They were able to win the first two of those games (3-2 at Carolina and 4-2 against Montreal) before suffering a 7-0 shutout at Winnipeg on Thursday.
Wolski cut the deficit in half at 15:48 of the second after a nice tic-tac-toe pass play with Marcel Goc and Fleischmann. He one-timed Goc's pass across the front of the crease with Rinne out of position.
But that's all the Panthers could muster against Rinne, who figures to get the chance to break the victory record Tuesday night at home against Los Angeles.
"So far it's so much fun to play," Rinne said. "We're coming together as a team. We've got a young group of guys and with the few experienced guys. We're having so much fun. And when you're having fun, you don't feel tired, especially when you're winning. Things are so much easier. Hopefully, we can keep it going.
"Obviously, you're always aware of how many wins you have because that's always a pretty simple stat, it's the most important stat. That's a team stat. We've been doing a good job together as a team. Hopefully, we can get a few more here."
1 - 0 NSH
2 - 0 NSH
2 - 1 NSH