George Ford kicked Leicester on to cloud nine, continuing their unbeaten start to the season with an 11-point haul to outclass Marcus Smith — the man who stole his England shirt.
In front of the biggest Welford Road crowd for three years, the Tigers clung on for a ninth consecutive victory.
This run, including the final day victory at Wasps last season, equals their longest stretch of victories in the Premiership — 10 in their winter pomp of 2001-02.
George Ford (centre) eclipsed Marcus Smith (left), the man who stole his England shirt, in the battle of the fly-halves as Ford's Leicester beat Harlequins 16-14 at Welford Road on Sunday
Ford kicked 11 points and controlled the game beautifully from No 10 for Steve Borthwick's XV
And Ford, who is leaving for Sale in the summer, was at the heart of a blood-pumping win, as Harry Potter scored Tigers' only try.
Louis Lynagh scored a try and Smith kicked the rest of Harlequins' points, but was sin-binned as Ford proved a diamond, trumping the visitors' playmaker.
'George adapted how we played after the first quarter,' said Leicester coach Steve Borthwick of Ford.