Inter Milan's big guns blasted the Serie A leaders to a 3-1 victory at Brescia yesterday, ensuring they remain two points ahead of closest challengers Chievo and AS Roma who also took maximum points.
Ronaldo opened the scoring for Inter with his first Serie A goal in two years and after Igli Tare had equalised for Brescia it was Christian Vieri, playing alongside the Brazilian for the first time in two years, who sealed victory with two second-half strikes.
"I am very happy - it's been a wonderful day," said Ronaldo.
Minnows Chievo, however, kept up the chase with a 2-1 home victory over Lecce at Verona.
Joint second with Chievo are champions Roma who owed their comeback 2-1 victory at Parma to goals from Assuncao and Diego Fuser after a Marco Di Vaio strike looked set to give the crisis club the points.
In the big evening clash at the San Siro it was honours shared as AC Milan and Juventus drew 1-1.
In Spain a goal either side of half-time from striker Ruben Navarro gave Alaves a 2-0 win at Real Zaragoza and three points that took them back to the top of the first division.
Alaves head the table with 30 points, one ahead of former leaders Deportivo Coruna who returned to winning ways when a 60th-minute penalty from Diego Tristan gave them a 1-0 win over Valencia at the Riazor.
Real Madrid are third on 28 points, level with Real Betis.
Barcelona surrendered a two-goal lead as they drew 2-2 with Celta Vigo in an absorbing tie at the Nou Camp last night.
The Catalan side got off to a flying start and took the lead after barely two minutes. Gabri made the most of some soft defending from the visitors and sent his shot bobbling past goalkeeper Pablo Cavallero.
Javier Saviola pounced for a second soon after the interval, but Celta pulled a goal back 16 minutes from time when substitute Sergi turned a cross into his own net. Celta eventually drew level through a header from Edu.
The result means that Barcelona are now seventh in the table, and have taken only two points in their last four matches.