Nottingham Forest needed to win that game to stay above the relegation zone in the table. They took advantage of the match from the start against Southampton, who are already in the relegation zone; it was too late for Southampton to recover and win again. It was an exciting game, and Nottingham Forest came prepared to win, which they did.
Southampton has one more match to secure their relegation fate this season. Nottingham Forest must also win their remaining games in order to return to the Premier League by next season. What a fascinating season, with a lot of team competitiveness for success even as the league is coming to an end.