The 30-year-old scored in each half at Pride Park Stadium to help oust Philip Cocu’s men out of the competition.
Ighalo’s deadline day move to Old Trafford from Chinese Super League outfit Shanghai Shenhua in January was greeted with derision and disbelief, but the Nigerian has netted three goals in just two starts for the Red Devils.
Speaking to the media after Manchester United’s win against the Rams, Solskjaer said Ighalo is proving to be a vital member of the squad as United are still sweating over injuries to some of their key players.
"He is doing what it says on the tin and what we asked for when we signed him," the Norwegian coach said.
"He is coming in, playing up front, and he's a different type of striker. He scores, he gets chances every game and today he could have had another couple. I am very happy with him.”
“It gives us a chance with Mason [Greenwood] and Anthony [Martial] to keep them fresh as well.”
"He is experienced and he has scored goals all of his career. He is in and around the box, he reads it, he sniffs out where the chances will come. I think that striker is vital for a team."
