Mark McLinden turned in a man-of-the-match display to inspire Harlequins to a deserved engage Super League victory.
There was a successful return from rugby union for Henry Paul, but skipper McLinden provided most of the spark and scored a magnificent solo try as his side edged home.
Quins went in at the interval 12-6 up after McLinden beat four Huddersfield players to score and David Mills crashed over from close range.
Stuart Jones and James Evans cut the deficit before two tries from Nick Bradley-Qalilawa crossed twice to make it safe for Quins.
The home side made their intentions clear from the outset, spreading the ball wide whenever possible, but handling errors proved their undoing early on.
Twice stand-off Luke Dorn threw wayward passes, one being intercepted and sending Huddersfield upfield.In their next set of six, captain Michael de Vere penetrated the home defence a little too easily but was unable to ground the ball.
Full-back McLinden then found the gap 25 yards from the Giants' line to put his side ahead and moments later Quins thought they had scored again.
Again pace was the key ingredient, Dorn reaching Thomas Leuluai's kick first before collecting and passing in one movement for Joe Mbu to cross the line
- however, the video referee ruled Mbu had been held up.
With half an hour gone the hosts spurned another chance, some loose passing culminating in McLinden flinging the ball straight into touch.
But sustained pressure enabled Leuluai to send Mills over near the posts.
Henry Paul came off the bench after 33 minutes with his new side in the ascendancy, Huddersfield holding their own up front but unable to find the final pass.
But the visitors got a try back just before the interval when Brad Drew kept his composure to set up Jones.
Quins were caught cold at the start of the second period, Drew darting downfield and gaining the field position from which Evans collected Robbie Paul's grubber to touch down.
The reply from Quins came after 50 minutes, Lee Hopkins offloading to Leuluai, who sprinted clear before giving Bradley-Qalilawa an easy score.
Robbie Paul wasted an opportunity for Huddersfield as an overlap went begging and Harlequins capitalised when Bradley-Qalilawa got his second, Henry Paul kicking the goal.
Stuart Donlan notched a try for the Giants two minutes from time, but it came too late to have a bearing on the result.