Before the game at the Santiago Bernabeu a minute's silence was held alongside a video showing Eusebio with Ronaldo and other Real Madrid greats such as Alfredo di Stefano.
And Ronaldo welcomed the tributes that have been made to the man nicknamed the "Black Panther".
"I want to thank everyone, especially to all the people in Spain for the homage they have paid to Eusebio. For the Portuguese it is very important to feel the warmth shown by the Spanish people," said Ronaldo.
"He was someone who was very close to me and obviously my goals today were dedicated to him. He helped me a lot with the national team and he is an example for us. It is very sad that we have lost one of the greatest players of all time."
Victory moved Real back to within five points of Barcelona and Atletico Madrid at the top of the Spanish La Liga.
However, the scoreline was flattering to Real as Celta passed up a host of clear-cut chances before Karim Benzema opened the scoring 23 minutes from time.
Ronaldo then took centre stage as he swept home late crosses from Dani Carvajal and Gareth Bale to take his tally for the season to 29.
Villareal win big
Ikechukwu Uche's hat-trick provided the inspiration for Villarreal to seal a slightly flattering 5-2 victory at struggling Rayo Vallecano.
Uche opened the scoring after just ten minutes and Hernan Perez's brace before half-time put the Yellow Submarine firmly on course for all three points, with Vallecano made to pay for poor finishing.
Uche then scored his second and third after the break to complete the rout, with Nery Castillo's double - the second from the penalty spot - for the home side proving mere consolation.