Quins extended their impressive start to the season by defeating the Rhinos 36-26, which leaves them for the first time top of the league.
However, Powell has not been tempted to claim all the praise, insisting that his players all had their own part to play in the London side's revival following last season's next-to-bottom place finish.
The 30-year-old, who is the youngest coach in Super League XV, gave former Quins coach Brian McDermott his first taste of defeat with the Rhinos - the Yorkshire giants second at the hands of their rivals at Headingley in three years.
"It's good to be at the top I suppose but it's early days and we've a lot to do," said Powell.
"I can't take much credit for tonight. It was a real team effort. The boys were so prepared and ready to play the game, they were buzzing before the game."