Niemi blanked the Predators for the second time, making 35 saves in a 2-0 victory at SAP Center. Tomas Hertl scored a second-period goal and Tommy Wingels had an empty-net goal for the Sharks, who won for the fourth time in their past five games.
"Nemo was very strong again tonight," Sharks coach Todd McLellan said. "He looks very confident, and the team feels good with him in there right now. He made some very difficult saves look easy. There wasn't a lot of leftovers laying around the crease areas."
The Sharks (34-26-8) are in fifth place in the Pacific Division, three points behind the third-place Calgary Flames. The Sharks also trail the Los Angeles Kings by three points for the second wild card into the Stanley Cup Playoffs from the Western Conference.
"You've got a little momentum, but you just got to bring it every night at this point," Sharks defenseman Justin Braun said. "You can't think about the last game. You just got to think about the next one going forward, get those two points."
Pekka Rinne made 19 saves for the Predators (42-20-7), who lost for the seventh time in their past eight games and fell into second place in the Central Division behind the St. Louis Blues. Each team has 91 points, but the Blues have played two fewer games.
"The guys played hard," Predators coach Peter Laviolette said. "The chances were in our favor, the shots in our favor, possession in our favor but we didn't get it done. Ultimately we need to win hockey games. We have to find a way to score, maybe create more traffic and try and get second opportunities. It's frustrating not to score."
Niemi had 29 saves in 2-0 shutout of Nashville on Dec. 13 at SAP Center. Rinne gave up one goal on 33 shots in that game.
"I don't know which one was tougher," Niemi said of the two shutouts against Nashville. "What I remember is it was different game. We had more chances that game compared to this game."
"We feel very, very good the last couple of games and everybody just thanks Nemo because he had a huge game for us," Hertl said. "I'm just so happy tonight because we need this game and just keep going and hopefully it continues the next games."
McLellan opened the power play with his second unit comprised of his third line -- Hertl, center Chris Tierney and Wingels -- along with Braun and Marc-Edouard Vlasic on the points. The move paid off.
Braun took a pass from Tierney and sent a wrist shot from the left point that Rinne stopped but couldn't control. Hertl buried the rebound from close range, putting the puck past Rinne's outstretched left pad for his 11th goal of the season. He ended a 13-game goalless streak by scoring for the first time since a two-goal game on Feb. 7 against the Calgary Flames.
"That line, that Tierney line, I thought was our best line tonight, as three, and our power play, our 'A' group or our first group, if you want to call it that, has been so strong all year; they really struggled tonight," McLellan said. "So it was an opportunity for that other line to get out there, and they got us the goal."
When the Sharks defeated Nashville on Dec. 13, Hertl scored the game-winning goal at 5:01 of the first period, beating Rinne.
"Same score," Hertl said. "I'm so happy. It's nice to score on Pekka Rinne because he is the leading goalie. It's nice to score against this guy. I'm just glad we won tonight because it was a huge game for us."
The Sharks had gone 0-for-3 on the power play before Hertl scored on their fourth chance with the extra man. Nashville didn't have a power play in the first two periods.
In three starts against the Sharks this season, Rinne allowed a total of three goals but lost two of the three games.
"We played well and had a good night but obviously came up short," Rinne said. "We created some chances but just couldn't execute tonight. Their goalie played well; they played well. We had our chances on the power play. We had enough power plays to create something, a tying goal, but that didn't happen."
Nashville went on its first power play of the game at 7:26 of the third period when Patrick Marleau went to the penalty box for holding Matt Cullen. The Predators, who had two power-play goals in their previous 35 attempts, came up empty again, but Niemi had to make four saves.
The Predators went on the power play again with 5:40 left when Melker Karlsson was penalized for slashing Cullen. The Sharks killed that penalty, allowing one shot on goal. Sharks forward Matt Nieto blocked a Shea Weber slap shot, and paid the price in pain.
"They capitalized on the power play and we didn't," Nashville defenseman Roman Josi said. "It's so important to make your chance count. We just have to find a way to score goals."
Niemi stopped Mike Fisher on a breakaway with 1:40 left in regulation, and Wingels scored into an empty net with 58.8 seconds left.
Niemi has struggled at times this season, but he's been playing his best hockey during the Sharks' playoff drive. He had 39 saves in the Sharks 2-1 shootout victory against the Pittsburgh Penguins on Monday.
"I've felt really good," Niemi said. "I think I've had a pretty good stretch."