The former Atletico Madrid goalie made 11 saves to keep Spurs’ attack at bay, with Marcus Rashford scoring the solitary goal and ensured they extend their winning run under new manager Ole Gunnar Solskjær to six games.
And the Nigeria international who spent three years with the Hornets, scoring 33 goals in 82 league appearances has lauded the sterling performance by the 28-year-old.
“You have to always hit it very hard and place it very well before you can beat De Gea,” Ighalo said on Sky Sports.
“He is the best in Premier League, he is the best in the world because he is a good goalkeeper, he has
Ighalo who scored 21 goals in 28 appearances last season for his Chinese side Changchun Yatai also eulogised goalscorer Rashford for his well-taken strike in the encounter.
“He is good, he is quick, he has good techniques and he can shoot from different angles,” he continued.
“He even scores free-kicks, so he is a good player. If you give him chance in that kind of area you don’t expect anything than scoring the goals.
“He is really doing well and I think he can push Manchester United a bit forward.”
Manchester United, sixth in the log with 41 points from 22 games, play host to Brighton and Hove Albion in their next League game on Saturday and De Gea will hope to continue the imposing form in the tie as the Red Devils aim for a top-four finish at the end of the season.