Che Adams rewarded Southampton's first half of dominance with the opener before Oriol Romeu completed off the Canaries with first purpose for the club on account that October 2020.
Norwich have lost nine of their 12 league games, leaving them caught 5 factors from safety.
Only three teams have averted relegation from the Premier League after losing as many as Norwich's 17 defeats by using this level of the season.
Having performed more games than any of the groups directly above them, it's far looking more and more not likely that Dean Smith's side will keep away from relegation to the Championship.
"It was a difficult night. We gave the ball away too affordably and when you do that you are going to be below strain within the Premier League," Smith said.
"It's a unhappiness due to the fact there's so many players that performed below the standards they could, and feature, played. All we can do is just focus on the subsequent game now."
Southampton have lost just once in 12 games in all competitions and sit down conveniently in mid-table.
Norwich have scored six goals fewer than every other facet in the division this season, even as most effective Leeds have a worse defensive file.
It failed to take lengthy for Southampton to start exposing their flaws.
Armando Broja examined Norwich keeper Angus Gunn from the brink of the place after Brandon Williams' wayward bypass conceded ownership.
