Southampton moves into 13th place with their big win over Watfordin Premier League action.
Danny Ings, who scored twice now has 18 goals on the season, one back of the League leader, Jamie Vardy of Leicester.
Substitutes made the difference as Chelsea and Arsenal both won away from home to reach the FA Cup semifinals on Sunday
Chelsea midfielder Ross Barkley turned in a cross from Willian midway through the second half in a 1-0 win at lacklustre Leicester.
Spanish midfielder Dani Ceballos netted an injury-time winner in a 2-1 win at Sheffield United, which had two goals ruled offside by video replay.
Ceballos pounced with a low shot, just four minutes after David McGoldrick had equalized from close range.
At Bramall Lane, forward Nicolas Pepe's penalty put Arsenal ahead midway through the first half, after United midfielder John Lundstram had an early header ruled out for offside. United defender John Egan's header early in the second half was also chalked off.
Arsenal has won the FA Cup a record 13 times, one more than Manchester United _ which squeezed into the semis with an extra-time win against 10-man Norwich on Saturday.
with files from (The Associated Press)