The Scot also scored in the opening-day victory over Leicester and bagged a hat-trick for Scotland against Malta last weekend.
He missed Hull's last season in the Premier League with a career-threatening knee injury and is making up for lost time with aplomb.
"He went through a real spell where it was serious...would he continue in this game?" he said.
"He's worked really hard, now he's scored a hat-trick for the national team and a perfectly-executed free-kick for his club in a week."