Real Madrid eased to a 2-0 win over Las Palmas on Wednesday to overtake Barcelona and move second, but Catalan minnows Girona are the surprise LaLiga leaders after after a 2-1 win at Villarreal.
Barcelona started the week top of the league but a 2-2 draw at Real Mallorca on Tuesday left the door open for their rivals to overtake them.
Madrid produced a comfortable victory with goals from Brahim Diaz and Joselu, while Brazilian winger Vinicius Junior also made his return from injury as a second half substitute, following a month out.
Real coach Carlo Ancelotti rested Jude Bellingham, who has been Madrid's best player so far, starting Diaz in attacking midfield in the England international's stead.
The Italian coach also swapped out both full-backs after the painful derby defeat by Atletico Madrid on Sunday, with Ferland Mendy and Nacho starting in place of Fran Garcia and Lucas Vazquez.
Real Madrid were on the front foot from the start against their promoted visitors from the Canary Islands, but lacked the killer finishing touch that Karim Benzema brought in recent years, and Bellingham has in recent weeks.
Striker Joselu, on loan from Espanyol, had various chances to break the deadlock but was repeatedly denied by excellent Las Palmas goalkeeper Alvaro Valles.
The stopper thwarted Diaz as he ran through on goal but took a heavy touch, while Rodrygo's effort was deflected narrowly wide.
Vazquez replaced the injured David Alaba, with Nacho moving inside to centre-back and the substitute played a part in the opening goal.
Valles stopped another Joselu drive before Diaz broke the deadlock, taking a touch to control Vazquez's cross and then firing into the top corner with the aid of a slight deflection.
Joselu made amends for his first half profligacy to pounce early in the second with a well-placed header from Rodrygo's cross that this time left Valles no chance.
Vinicius made his return with over half an hour remaining as Ancelotti reverted to a 4-3-3 system, having begun with the midfield diamond he has favoured this season.
Aurelien Tchouameni came close with a long-range effort and Madrid saw out the game without incident to move one point ahead of Barcelona.
Michel's Girona came from behind to beat Villarreal, with on-loan Barcelona defender Eric Garcia netting the winner.
Dani Parejo sent Pacheta's struggling Villarreal ahead from the penalty spot, before Ukrainian striker Artem Dovbyk levelled for Girona and Garcia headed home after an hour.
Real Madrid visit Montilivi on Saturday in a mouthwatering clash between the top two, while Barcelona host Sevilla Friday.