But after failing for much of the game to give their attack any sort of structure, Hull then set about trying to construct the unlikeliest of comebacks.
With the clock ticking past the 70 minute mark, Richard Horne touched down after fullback Shaun Briscoe had found his halfback with a sharp flick pass to put Horne into acres of space.
Just two minutes later England schoolboys centre Craig Hall cut the home side's lead to six when he scored a try and then converted to set up a grandstand finish.
The travelling fans thought their Good Friday was about to get a whole lot better when former Australian winger Matt Sing crossed in the corner after Sid Domic hit his fellow antipodean with a sublime pass to allow Hall the chance to make a name for himself in his Super League debut.
However the youngster was unable to guide his match-tying conversion attempt between the posts, and the score remained 30-28 until a relieved Harlequins side heard the fulltime whistle.
It was something of a baptism of fire for Hall who had his first senior start in the Challenge Cup against Hunslet and amassed 34 points.
But his kicking boots had clearly been left on the bus as he landed just two goals from six attempts.
His Australian coach Peter Sharp was pragmatic about his teenager’s efforts.
"People say he is just a kid, but he is in the side to kick goals and he didn’t kick goals," Sharp lamented.
Hull's Richard Horne scored two tries against
Quins, but it wasn't enough [GALLO/GETTY]
"This is Super League and people’s careers are on the line, but having said that he is a terrific talent and really is just a baby."
Sharp, who enjoyed such a stellar run with the side last year, was left frustrated after the match.
"The game was there for the taking, but they ran a bit harder than us, tackled a bit harder and kicked a lot better than us."
His counterpart Brian McDermott felt his side deserved to return to the winner's circle.
"I felt we were the better team for 65 minutes, before Hull came right back into it as they had every right to do, as they are a good team," said the Quins coach.
While they stumbled before crossing the line, McDermott didn’t feel Rugby League awarded points for style.
"It was a bit ugly at times, but we did the job."
To be fair, at other times it looked quite attractive as the Harlequins took the match by the scruff of the neck after Domic had scored the first try for the visitors.
Tries to Jon Wells, Daniel Heckenberg, Andy Smith and Julien Rinaldi put the London outfit in complete control as dual international Henry Paul slotted over five of his six conversions.
In the end it was the accurate boot of Paul which made the difference as both sides now attempt to recover for the next round of matches, which will be played on Monday to take advantage of the Easter holiday.