Leicester bagged a remarkable 19-14 comeback win at Worcester courtesy of a last-gasp penalty try at a sold-out Sixways Stadium.
The visitors notched three tries to the Warriors' one but Andy Goode outclassed Toby Flood with the boot to help Richard Hill's hosts to within sight of victory - only for late drama to take the Tigers top.
The early stages were quiet bar a 10th-minute Goode penalty, but Sixways erupted four minutes later - excellent footwork from centre Jon Clarke putting Chris Pennell into the space he needed to send David Lemi diving over in the corner unopposed.
The boot of Goode then knocked over a penalty harsh on the burrowing Martin Castrogiovanni, and the Italian's evening got worse moments later when he flung himself into tackling Semisi Taulava - referee JP Doyle ruling that he had failed to use his arms in the challenge and issuing a yellow card.
At this stage, Leicester fly-half Flood was being comfortably outplayed by veteran counterpart Goode in front of watching England coach Stuart Lancaster, and his first attempt to put the Tigers on the board fell short of the target.
On the stroke of half-time, Leicester gave themselves hope when Dan Bowden expertly delayed his pass to Mathew Tait, who ghosted inside his man and provided Scott Hamilton with a routine finish.
Goode blotted his copy-book as Hamilton touched down with a knee-drop that was picked up by referee Doyle, and the former Tiger looked on from the sin bin as his successor Flood fell short again both with the conversion and with the penalty re-start to leave it 14-5 at the break.
The absence of Goode was immediately apparent in the second period with deputising kicker Pennell missing a pair of routine penalties and negating more determined Warriors work up front, but Leicester failed to make the man-advantage tell at the other end.
Tom Croft's low-key return to action ended with Julian Salvi's 53rd-minute introduction, and more fresh legs in the visiting pack helped earn their first penalty try before the hour mark - Dan Cole and Marcos Ayerza entering the fray to help annihilate the Worcester scrum on their own 5m line.
Flood's conversion from in front made it 14-12 but the game seemed to be slipping away from the Tigers when he was again short with a penalty eight minutes from time after Pennell's flailing arm had caught Tait square on the nose.
Typically, Leicester refused to accept defeat, forcing a turnover deep in their own territory which the bloodied Tait ran downfield to spark a move that resulted in another 5m scrum, where the Tigers had a clear edge.
Worcester may claim Ben Youngs tapped the ball back into the scrum illegally, but Doyle saw fit to award a second penalty score from a close-range set-piece and decide the game in favour of Leicester.