Southampton's relegation from the Premier League was confirmed following a 3-1 defeat by Tottenham on Sunday.
Brennan Johnson scored twice at the Tottenham Hotspur Stadium, while Mathys Tel was also on target from the penalty spot to consign Ivan Juric's side to an immediate return to the Championship.
The Saints are the first side in Premier League history to be relegated with seven matches still to play.
Johnson did the damage with a first-half brace, rounding off a swift counter in the 13th minute, and doubling his tally by volleying home just before half-time.
Mateus Fernandes halved the deficit with a neat finish in the 90th minute, but after Welington felled Johnson in the box, Tel's stoppage-time penalty ended Spurs' four-match winless league run.
Ange Postecoglou's side, who had dropped to 16th place following Saturday's results, climbed to 13th, with Southampton remaining rooted to the foot of the table.
Data Debrief: Unwanted history for sinking Saints
Southampton have now been relegated in two successive Premier League campaigns, having only suffered the fate twice in their first 45 top-flight seasons.
Losing for the 25th time in their first 31 games, the Saints are only the third team to do that in a Premier League season after Sunderland (2005-06) and Sheffield United (2020-21).
With his brace, Johnson took his Premier League goal tally for the campaign into double figures (11), achieving the feat in a league season for the third time in his career.
Tel sealed the victory and, aged 19 years and 344 days, became the first teenager to score for Spurs in the top flight since Dele Alli in April 2016 (19 years and 365 days against Manchester United).