Redknapp, who celebrated Pompey's 21st clean sheet of the season, added: "Niko's an outstanding footballer, real class. You all saw the goals he scored against England and Scotland for Croatia.
"Although we were without Diarra who had a dead leg, and Jermain Defoe who has gone to his nan's funeral, we found a system that suits us. I think it is our 13th away win in all competitions this season.
"West Ham will be okay. They are 10th despite a lot of injuries and it's much better than last season for them. they have a strong squad.
"I took West Ham to fifth spot once when I was here and it would be nice to do the same with Portsmouth.
"We've come a long way in the last few years. I've come back three times here and won now and the buzz is still as great."