Southampton were relegated from the Premier League after losing 2-0 at home to Fulham on Saturday, bringing an end to their 11-year spell in the English top flight with two games remaining in the season.
Carlos Vinicius opened the scoring at St Mary's Stadium three minutes after halftime, with Aleksandar Mitrovic, who came off the bench for Vinicius, doubling their advantage to seal Southampton's fate.
Southampton, who had needed a win to stave off relegation, can no longer reel in 17th-placed Everton and Ruben Selles's side are bottom of the league on 24 points from 36 games.
The south-coast club earned promotion to the Premier League in 2012 and finished in the top eight for four straight seasons between 2013-17, but have earned only six league wins this season, racking up 24 defeats and six draws.
"Disappointing. It has been coming. We knew we were in a difficult position," Southampton captain James Ward-Prowse told the BBC.
"We need to go away individually and as a club and assess if we've done everything we possibly could. I don't think we have and that is a shame.
"I think we should perform at a better level than we have done. From the first day of the season until now you can tell the standards have slipped."
In a scrappy and disjointed opening 45 minutes, neither side could take control of the game, with Fulham having more possession and slightly better attempts but no luck in front of goal.
The best chance of the first half came when Willian unleashed a volley from close range in the 41st minute but Southampton defender Lyanco cleared the effort off the line.
Both sides tried to play with more attacking intent in the second half, as Carlos Alcaraz had a goal disallowed before Vinicius latched on to a loose ball in Southampton's box and tapped home in the 48th minute.
Mitrovic marked his return from an eight-match ban with a stooping header in the 72nd minute.
Southampton had the lion's share of possession in the closing stages but were unable to create anything of note and prevent a return to the second-tier Championship. British Prime Minister Rishi Sunak, who was born in Southampton, was one of the few fans who did not leave the stands before the final whistle.
Fulham moved up to ninth and stayed on course for a first top-half finish since 2012.
"We controlled the game until the last minute. We had one or two good chances to score before the 1-0 and then we scored the second," Fulham boss Marco Silva told Sky Sports.
"We knew before the match they were in a difficult situation and it was the last chance for them to keep believing with the supporters behind them but we took the ball from them in the first minute."