Rodrygo scored twice to lead Real Madrid to its first Copa del Rey title in nearly a decade after overcoming Osasuna 2-1 in the final.
Rodrygo was set up by fellow Brazil forward VinÃcius Júnior to give Madrid the lead just two minutes after kick-off at La Cartuja Stadium.
Osasuna's Lucas Torró equalized in the 58th, but Rodrygo put Madrid back ahead for good in the 70th.
With the Spanish cup in hand, Madrid will host Manchester City on Tuesday in the opening match of their Champions League semifinal.
Since winning its last Copa del Rey in 2014, the 14-time European Cup winner had won four Champions Leagues while falling short in the Spanish cup.
That changed on Saturday, when it defeated an Osasuna that was seeking its first major title in club history after also losing its only other Copa del Rey final in 2005. Madrid has 20 Copa del Rey titles, behind only Barcelona (31) and Athletic Bilbao (23).
Now it can seek a cup double if it can get past City for a second straight season and successfully defend its continental title.
"We had been talking all week about how it had been a long time since Real Madrid had won this title," Rodrygo said. "I really wanted to win this title since it was this that was the only (club) title I was missing."
Just 22 years old, Rodrygo, like many of his teammates, has completed their collection of club titles after having already won the Champions League, Spanish league, Club World Cup, UEFA Super Cup and Spanish Super Cup.
Captain Karim Benzema received the cup from Spain's King Felipe VI, who attended the coronation of King Charles III.
Rodrygo was key to Madrid's run to its record-extending 14th-European Cup last season. And against Osasuna he proved clutch in yet another big match, especially when cued by countryman VinÃcius.
VinÃcius dribbled past both Jon Moncayola and Rubén Peña before slipping the ball past three other defenders to find Rodrygo in the middle of the area to score the early opener.
VinÃcius continued to escape his markers and Moncayola, a midfielder converted into a left back, soon got a yellow card for pulling him down from behind.
"It is very tough to defend VinÃcius as City will see on Tuesday," said Osasuna coach Jagoba Arrasate, who wept after the final whistle from what he said was the "built up tension."
But Osasuna, a modest club from Pamplona in northern Spain, had its chances, too.
Abde Ezzalzouli came close to leveling in the 26th when he broke past the defense and chipped goalkeeper Thibaut Courtois, only for Dani Carvajal
to rush back and clear to safety.
The action didn't stop as David Alaba surprised with a long free kick that rattled the crossbar in the 28th.