An early own goal from Daniel Wass set up the victory with Lucas Vazquez making sure of the points shortly after Isco's introduction, with Madrid grateful to goalkeeper Thibaut Courtois for key saves.
Isco has not started for Madrid since Solari succeeded Julen Lopetegui, although he has been recovering from surgery on his appendix.
And Solari, who has regularly been forced to deny a rift with Isco, again praised the midfielder despite preferring to name Marcos Llorente and Dani Ceballos in his XI.
"He would be decisive when we had a transition," Solari, who introduced Federico Valverde before Isco, said to Movistar.
"[I am] satisfied with him and with everyone."
Marcos Llorente again shone in midfield, completing 100 per cent of his passes in the Valencia half, having thrived in the 2-0 win at Roma.
Casemiro and Toni Kroos were absent due to injury and Solari is pleased to have a range of options for Madrid's midfield.
"It's fantastic, it's what makes teams solid and big, the big ones play many competitions," Solari added.
"It's a lot of games and it's important that each of the players is fit and cheerful and available. Two great games that he had to play."
Real Madrid C.F. (@realmadriden) December 1, 2018
Gareth Bale, meanwhile, saw his goalless run in La Liga stretch to 10 matches, his longest sequence without a goal since joining Madrid .
Solari replaced the Wales star early in the second half and said Bale was withdrawn for physical reasons rather than as a tactical decision.
"He is tired and had some discomfort, he gave a lot in Eibar [last weekend's 3-0 loss], in Rome and today, it is normal that he is exhausted," Solari continued.
"This support always demands more from everyone. I would like to focus on the players who have excelled - Karim, Llorente, Lucas, Courtois, the central players, the wingers, a very complete game from all."