The Argentine's wonderful solo effort against the 'Terriers' was the undoubted highlight of Saturday's clash.
It was Pereyra's fifth goal of the season; the South American one of those flourishing under Gracia's tutelage.
"When I arrived in January, from that moment Roberto is keeping a high level in all the performances. He's scoring a lot of goals, he is working very hard," said Gracia.
"For example last game after playing with the national team and coming back on Thursday he played an amazing game against Wolverhampton, scoring an amazing goal.
"It is not a surprise to me because I see in all the training sessions his commitment, his ambition."