Schenn scored in overtime to give the Blues a 1-0 victory the previous time the teams played.
The Predators tied it at 2:36 when Sissons was left alone during a bad Blues line change.
Saad put St. Louis back on top with a backhand shot between Saros' legs at 8:30. St. Louis rookie Tyler Tucker assisted to earn his first NHL point.
Kyrou also used a backhand to score a power-play goal at 15:34. He has 10 points (five goals, five assists) in nine games against Nashville.
The Blues added two quick goals in the third. Thomas scored at 1:03 and Toropchenko followed at 2:01.
Nashville's final goal came from Ekholm at 17:52.
A goal by Nashville’s Tommy Novak was overturned when officials ruled goaltender interference at 2:03 of the first period. Jeremy Lauzon made contact with Binnington before Novak tapped in a rebound.
The Blues had 33 shots on goal. They had been held under 30 for seven straight games. ... Nashville failed on its three power-play chances and is 1 for 24 over its last eight games. ... RW Vladimir Tarasenko (hand), D Torey Krug (lower body), D Robert Bortuzzo (lower body), D Marco Scandella (hip) and LW Logan Brown (upper body) all participated in Thursday morning's optional skate for the Blues. None played against Nashville. ... The Blues wore their white road jerseys at home for the second and final time this season. ... The Predators reassigned D Roland McKeown to the Milwaukee Admirals of the AHL. ... Nashville D Mark Borowiecki (upper body) sat out. ... Blues C Nikita Alexandrov (upper body) is day-to-day.
Predators: Host the Los Angeles Kings on Saturday.
Blues: Host the Chicago Blackhawks on Saturday.
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Warren Mayes, The Associated Press