Relaxed approach paid off for Rhinos
Leeds led at the interval courtesy of Brent Webb's double and Ryan Hall's score but it was their nervy, error-strewn showing that will have caused concern at the interval.
But nine tries in a devastating second half signalled the Rhinos' return to form in a 62-4 victory.
Advertisement
Hide AdAdvertisement
Hide Ad"It's good to see the players enjoying themselves and expressing themselves and I thought we were able to pass the ball a bit and scored some nice tries," said McClennan.
Attempting to explain his side's slow start, the Rhinos coach added: "We tried too hard. We made a lot of line breaks but we just didn't execute well. We got a bit impetuous and tried one pass too many.
"I think that's what we did better in the second half. When we made splits, we didn't think we had to score, we made better decisions with the football."
Leeds took their frustration from the previous Sunday's World Club Challenge into Friday's game after victorious Melbourne's tactics prevented them from gaining any momentum in attack.
Advertisement
Hide AdAdvertisement
Hide AdHarlequins, who have now won only one of five outings so far this season, currently have seven players out through injury. Coach Brian McDermott admitted it is hugely frustrating and accepted he cannot expect any more from his team until some of his key players return.