The Hammers’ left-back replaced the suspended Arthur Masuaku at the London Stadium and scored a curling freekick in the final 10 minutes to help secure the three points.
Fredericks praised the 29-year-old, who was solid in helping his team keep a clean sheet, as well as providing a constant outlet going forward out wide.
“Then, obviously, Cress chipped in with an amazing goal,” he told the club’s official website.
“I’m buzzing for him. He’s been waiting for a chance for a few weeks and now he’s come in and taken it.”
West Ham jumped into fifth in the Premier League after the victory, which saw them extend their unbeaten run in all competitions to six games, keeping four consecutive clean sheets in the process.
After Cresswell’s solid performance against United on Sunday, it is hard to see any way straight back into the starting line up for Masuaku after his suspension. The 29-year-old was impressive in all departments against the Red Devils, and Manuel Pellegrini will have no reason to make any changes for the next Premier League game. United had little threat in the game, and the Hammers defence made sure of that – with Cresswell making three tackles and two clearances in the game according to WhoScored, which helped nullify their threat consistently. The English full-back also gives West Ham a different threat from set-pieces, something he highlighted perfectly when curling the ball beyond David De Gea to seal all three points. After the convincing performance in East London, it is hard to make a case for Pellegrini making any changes for the trip to Bournemouth on Saturday – something that would see Cresswell make his third appearance of the season.