Parker scored the third goal in an all action display to help his team secure their first victory in the Premier League since the end of September.
Parker’s performance was all the more impressive as Grant revealed the midfielder had been struggling with an injury before the game.
"He had a chest infection. He was great. He is a player I like very much. He has an all-round game,” said Grant.
“He is a good, old-fashioned English footballer always giving 100 per cent. He was sick today but he still gave everything.
“He wanted to play and played very well scoring an exceptional goal. He is the modern midfield player putting in tackles, scoring goals, giving assists.”
West Ham’s first win in nine attempts in the Premier League was not enough to lift them off the bottom of the table after Wolves defeated Sunderland but Grant was pleased with the performance.
"It was a big win against a good side. We were more efficient today. The performance was more efficient today,” he added.
“We started a little bit nervous but that is understandable considering our position in the league and the result against Liverpool.
“The players tried to do the right thing always fighting and I am very happy because of the response to last week's defeat.
“We are building a strong mentality here and that will help us.”
Grant also seemed unconcerned that his team remained bottom of the league, believing that it is too early in the season to get too worried about the situation.
“We have only played 15 games so it doesn't matter. We need to our job and it is the last ten to eight games that are important. There are still 20 games to go until the end of the season."