MANCHESTER, England : Manchester United fought back from 1-0 down to overpower West Ham United 3-1 and reach the FA Cup quarter-finals as Premier League Tottenham Hotspur and Southampton suffered shock defeats on Wednesday.Three days after they won the League Cup Manchester United trailed to Said Benrahma's 54th-minute goal at Old Trafford but an own goal by West Ham's Nayef Aguerd and late strikes from Alejandro Garnacho and Fred sent the hosts into the last eight.Tottenham suffered a 1-0 loss at Championship side Sheffield United after Iliman Ndiaye scored 11 minutes from time to stun the visitors.Grimsby Town, 16th in League Two, continued their dream FA Cup run as two penalties by Gavan Holohan knocked out Southampton on their own ground and sent the fourth-tier side into the last eight for the first time in 84 years.Championship leaders Burnley beat Fleetwood Town 1-0 in the other tie to join Manchester City, Brighton & Hove Albion, Fulham and Blackburn Rovers in the quarter-finals.