The clinical striker is back from a long absence and scores in Benzema's absence to leave Mourinho with problem of plenty.
Higuain gain is selection pain for Mourinho at Real Madrid
It is easy to forget that Gonzalo Higuain is only 23. The Argentine is already in his eighth season as a professional footballer and if it seems a long time since he moved from River Plate to Real Madrid, it's because it is.
The Real of late 2006, which Higuain joined, is unrecognisable from now. The kit is still white and the Santiago Bernabeu is still home, but Higuain has survived several changes of coach and, despite his youth, is now Real's longest-serving foreign first teamer.
Of the Spaniards, only Iker Casillas and Sergio Ramos have been at the Bernabeu longer.
The striker was just 18 when he moved from Buenos Aires to Madrid in a €13 million (Dh63.7m) transfer. It was not the first time he had been in Europe. The son of professional footballer Jose Higuain, he was born in Brest, France, where his father played, in 1987.
After a tricky start in Spain, Higuain got better and better as he matured. He won the Spanish league in each of his first two seasons and was Real's top scorer before the arrival of Cristiano Ronaldo in 2009. The advent of the Portuguese star aided and improved his game - Higuain scored 27 league goals in 2009/10.
His reputation as a clinical and effective striker who exploited space behind defenders was just, but then a herniated disk injury was diagnosed in November 2010 following Real's 5-0 defeat at Barcelona's Camp Nou.
After initial complications and accusations of misdiagnosis, he underwent an operation, coming back towards the end of the season, by which time Karim Benzema had found form, and was the favoured striker along Ronaldo.
An injury to Benzema meant Higuain started his first game of the season at Espanyol late on Sunday night.
It was only his second start in a year, but he reacted magnificently, combining effortlessly with Ronaldo to score three outstanding goals in a 4-0 victory.
Higuain clutched a signed match ball in the mixed zone after the game in which he acknowledged that: "Everybody knew I needed this after my injury."
He had further reason to smile after seeing headlines like "Higuain is dynamite." Jose Mourinho congratulated him too - it will be up to him how much he plays from now on, but a free scoring Higuain presents him with a strike dilemma other coaches must envy.