Teenager George Ford drove Leicester into a remarkable eighth successive Premiership final as Tigers ended Saracens' reign as English champions with a 24-15 success.
The 19-year-old, son of former England defence coach Mike Ford, kicked four penalties and a conversion after replacing ankle injury victim Toby Flood.
Ford's inclusion was the headline selection by Tigers, especially as they had named Flood on their official team sheet on Friday, but he did not let down a club in pursuit of its 10th league title.
In addition to his priceless points from the boot, Ford also created both Leicester tries through slick passing that cut open a Saracens defence renowned for its Scrooge-like quality.
Wing Alesana Tuilagi, on his final Tigers appearance at Welford Road before moving to Japan, touched down midway through the first half, while flanker Steve Mafi also crossed to thwart a Saracens side whose points came from five Owen Farrell penalties.
Leicester slumped to 11th in the Premiership after their first six games, of which they lost five, but 14 subsequent victories and a draw saw them climb to just one point behind regular season leaders Harlequins.
And it was Ford, current junior world player of the year, who showed admirable maturity to steer Leicester towards a Twickenham appointment with Quins on May 26.
England international Flood will probably return for the final, yet there can be no doubting Ford's contribution to Tigers during a season when he also kicked 16 points in their LV= Cup final victory over Northampton.
Saracens, despite leading 12-10 just before the break, were punished for their failure to convert a number of promising attacking positions into points.
And Leicester needed no second invitation to capitalise as fortress Welford Road once again lived up to its reputation for visiting teams.