Carlo Ancelotti's side were at their devastating attacking best at the Riazor, with a Gareth Bale double, James Rodriguez's first Liga goal and a late brace from Javier Hernandez supplementing Cristiano Ronaldo's hat-trick.
Defeats to Real Sociedad and Atletico had put Ancelotti under some pressure, but after a morale-boosting 5-1 UEFA Champions League win over Basel on Wednesday, the European champions never looked like falling to a third straight Liga loss.
Real went in three to the good at half-time courtesy of two goals from Ronaldo that sandwiched Rodriguez's superb 20-yard left-foot strike.
But any hopes of a comeback were dashed by Bale, who restored Real's three-goal advantage with 24 minutes to go.
Bale doubled his tally in the 74th minute and Ronaldo completed his treble soon after, before on-loan Manchester United striker Hernandez came off the bench to add further gloss to the scoreline after Toche had grabbed a consolation for the hosts.
The Spanish champions were beaten 3-2 by Olympiacos in the Champions League on Tuesday, and their disappointing week continued as Celta earned a share of the spoils.
However, Miranda undid his good work by giving away a penalty early in the second half, which was subsequently converted by Nolito.
Atletico piled the pressure on in the latter stages, forcing Celta goalkeeper Sergio Alvarez into several saves before substitute Alessio Cerci had an injury-time goal disallowed for offside, but they had to settle for a point in the final game of coach Diego Simeone's touchline ban.
Jhon Cordoba's first-half strike was all that separated the two teams at San Mames.
Cordoba struck six minutes before half-time, firing the ball between Iraizoz's legs as Bilbao crashed to back-to-back Liga defeats.
