"They were absolutely brilliant in the first half," he said after the 4-2 win that took the Hammers back in to third spot in the table.
"We're a young team and performed well, but we need to be a little more ruthless.
"We started the second half well, but then our inexperience let us down and they came back at us.
"We have to be more assertive and mentally strong to really finish teams off. We didn't take our chances.
"We are putting together a fantastic team that can put pressure on the top two sides, which is good news," he added.
"They are really getting into a groove and that's what you need going into the play-offs."