Harlequins lost their undefeated home record in the Aviva Premiership as Leicester ran out deserved 27-18 winners at the Stoop.
Leicester had trailed 13-3 at the interval but a yellow card for home full-back Aaron Morris and a strong second half performance from Tigers ensured that Quins were beaten at home for the first time this season.
Sam Harrison and Freddie Burns scored Tigers' tries. There was also a penalty try award with Burns converting two and kicking two penalties. Owen Williams added a conversion.
Alofa Alofa and David Ward scored tries for Quins with Nick Evans converting and kicking a penalty. Ruaridh Jackson added a penalty.
Leicester started brightly and should have taken an early lead when bursts from Harrison and Greg Bateman had the home defence firmly on the back foot but some careless passing allowed Quins to keep their line intact.
It was all Leicester in the opening 15 minutes as the hosts struggled to get out of their own half with the concession of a couple of scrum penalties not helping their cause.
A poor cross-field kick from Evans ensured that Tigers maintained the pressure and they deservedly took the lead when Burns kicked a penalty.
From the restart, Marland Yarde gave away another penalty for a foolish push and the visitors were back in Quins' territory but eventually the home side released the stranglehold by breaking into the opposition 22 for the first time, but it had taken them 23 minutes to do so.
However, they immediately made it count by winning a penalty, which Evans kicked to level the scores before they took the lead with a fortunate try.
Morris and James Chisholm made penetrative runs but when Matt Hopper kicked ahead, the ball looked certain to run into touch goal but it rebounded straight back off the corner flag for Alofa to secure the touchdown which was converted by Evans.
Quins suffered a blow when Evans was helped off with an arm injury to be replaced by Jackson. It was rough luck on the outside half for it was his first game for seven weeks after being injured in the home win over Sale in early January.
Jackson's first task was to succeed with a simple penalty before Burns was short with a long range attempt to leave Tigers trailing 13-3 at the interval.
Quins let the restart kick bounce which gave early second half momentum to Tigers and they capitalised when Harrison forced his way over from close range, with Burns adding the extras. Hopper conceded a needless penalty by throwing himself into a ruck before elusive running from Maxime Mermoz kept Leicester in the ascendancy.
A well-judged cross-field kick from Burns saw Adam Thompstone leap to collect only for Morris to clatter into him. The full back was yellow carded and referee Dean Richards awarded a penalty try which Burns converted to give Leicester a 17-13 lead.
Leicester brought on Tom Youngs and Mike Williams to strengthen their pack with Owen Williams temporarily replacing Thompstone, who was felled heavily in the collision.
A second penalty from Burns extended the visitors' lead before Thompstone and Morris were able to return just in time to see Burns intercept and race away to seal victory for Leicester. Williams added the extra points.
Luke Hamilton picked up a late yellow card as Quins staged a spirited rally to earn a try from Ward but Jackson's missed conversion deprived them of a bonus point.