Florentino Luis has signed a new contract with Benfica, which doubles his release clause from €60 million to €120m (£107m/$136m).
The highly-regarded defensive midfielder had emerged as a summer transfer target for Manchester City and Paris St-Germain but will instead stay with the Portuguese champions.
Benfica had been concerned about the prospect of losing Florentino ahead of time, with his release clause set tantalisingly low, but succeeded in agreeing terms with the 19-year-old on the first day of pre-season, July 1.
Forward Joao Felix is all set to join Atletico Madrid imminently - the club who earlier this summer lodged a €126m (£113m/$143m) offer to sign the Portuguese - and Benfica were determined to hang on to their other academy crown jewel this summer.
Florentino, whose previous deal extended through to 2023, has signed new terms to 2024.
The Portugal U20 international told Benfica TV: "I look at my progress in training with great pride because it has been very good. I was fortunate to have great conditions, coaches and colleagues who helped me evolve with each training session and every game to get where I am now.
"We have goals, but we always try to do things step by step, to live in the present, because if we do not, we can hardly achieve what we want."
The Benfica youth product established himself in the Benfica team in the second half of the season, with nine Primeira Liga starts, as his club reclaimed the Portuguese title from Porto.
Manchester City have kept track of his progress and he was seen as a potential long-term replacement for Fernandinho in Pep Guardiola’s midfield. However, Atleti’s Rodri is the immediate priority in that position .
Adrien Rabiot’s free transfer to Juventus has been confirmed and PSG had been in the market for a midfield replacement. Florentino is also admired at Parc des Princes.
Roma, meanwhile, are building for the future under new coach Paulo Fonseca and sporting director Gianluca Petrachi and had looked at Florentino as a potential centrepiece in their revival.
Florentino has been a mainstay in the Portuguese national youth setup, being part of the winning UEFA European Under-17 Championship team in 2016 and the European Under-19 Championship team in 2018, and appearing in the team of the tournament at each of those competitions.