Tanner Jeannot had two goals and two assists, Alexandre Carrier had a goal and an assist, and Filip Forsberg had three assists for the Predators. Juuse Saros made 27 saves in his first start of the preseason.
Brandon Hagel scored, and Hugo Alnefelt made 21 saves for the Lightning, who also lost 2-0 here on Thursday.
Jeannot gave Nashville a 1-0 lead at 5:54 of the first period with a power-play goal, and Carrier made it 2-0 with a power-play goal of his own at 7:00.
Colton Sissons extended the lead to 3-0 at 18:21.
Duchene made it 4-0 at 17:11 of the second period, and Jeannot scored his second power-play goal of the game at 2:26 of the third period to make it 5-0.
Hagel scored for Tampa Bay to make it 5-1 at 4:11.
Duchene's second of the game made it 6-1 at 5:09, and Zach Sanford scored at 6:33 for the 7-1 final.
Capitals 2, Red Wings 0: Darcy Kuemper made nine saves in 31:30 in his preseason debut for the Washington Capitals, a 2-0 win against the Detroit Red Wings at Little Caesars Arena in Detroit.
Kuemper signed a five-year, $26.25 million contract ($5.25 million average annual value) with the Capitals on July 13 after winning the Stanley Cup with the Colorado Avalanche last season.
John Carlson had a goal and an assist, and Alex Ovechkin had four shots in 18:10 in his preseason debut for Washington. Charlie Lindgren made 10 saves in relief.
Ville Husso started and made 13 saves in 31:30 for Detroit. Victor Brattstrom allowed one goal on 17 shots in relief.
Carlson gave the Capitals a 1-0 lead at 13:35 of the second period.
Lars Eller scored an empty-net goal at 18:54 of the third period for the 2-0 final.
Sharks 7, Golden Knights 3: Danil Gushchin scored a hat trick for the San Jose Sharks in a 7-3 win against the Vegas Golden Knights at T-Mobile Arena in Las Vegas.
The 20-year-old forward, who was a third-round pick (No. 76) in the 2020 NHL Draft, has five points (four goals, one assist) in two games this preseason.
Erik Karlsson had a goal and an assist, Timo Meier had four assists, and Tomas Hertl had two assists for the Sharks, who also lost a split-squad game 4-1 to the Anaheim Ducks on Friday. James Reimer made 27 saves.
Jack Eichel had two goals and an assist, Reilly Smith had a goal and an assist, and Phil Kessel had two assists for the Golden Knights. Adin Hill made 32 saves.
Mark Stone, who had back surgery this offseason, made his preseason debut for Vegas. He had one assist in 15:59 of ice time.
Karlsson gave San Jose a 1-0 lead at 6:26 of the first period, but Eichel tied it 1-1 at 18:30.
Gushchin made it 2-1 at 5:35 of the second period before Matt Benning pushed the lead to 3-1 at 8:59.
Jonah Gadjovich scored 57 seconds later to make it 4-1.
Smith converted on a power play at 13:34 to get Vegas to within 4-2, but Gushchin restored the three-goal lead at 15:41.
Eichel scored his third goal of the preseason 51 seconds into the third to cut it to 5-3.
Gushchin completed the hat trick to extend it to 6-3 at 4:37, and Luke Kunin scored at 11:48 for the 7-3 final.