The Spanish league returns after a two-week hiatus. Barcelona and Atletico Madrid lead the league with 40 points, and a rejuvenated Real Madrid are only three points behind. Atletico and Barcelona are scheduled to meet in January.

Neymar is finally taking command of Barcelona's attack with Lionel Messi out injured. The Brazil striker finally scored in the Champions League after six games, notching a hat-trick in Wednesday's 6-1 victory over Celtic. "I needed a game like this," Neymar said. "Let's hope I can keep it going."

Neymar's performance featured all of the qualities Barcelona supporters were waiting for from a player the club paid 57 million euros ($74 million) for.

"He's getting better and better," Barcelona coach Gerardo Martino said. "That (first) goal lifted his confidence and after that he deployed his entire repertoire."

Neymar has played mostly on the left wing but has also been moved into the middle of the field, an area where Messi creates many of his goals.

"His capacity to compromise for the interests of the team continues to surprise me," Martino said, "that's usually something foreign to players of his standing."

Barcelona's 6-1 win over Celtic certainly seems to indicate the Spanish co-leaders have emerged from their first slump of the season.

"It was our most complete game played in these first four months of the season," Martino said. "We pressured well, played with intensity."

Barcelona have won two straight games since losing two in a row to recover their confidence going into another complicated league contest, with Villarreal visiting the Camp Nou.

Villarreal, meanwhile, are fifth in the league and go into Saturday's contest after beating Indonesian club Mitra Kucar 13-0 in a midweek friendly match.

Atletico continue to show no signs that their season-long form is a fluke.

The "other" Madrid club beat FC Porto 2-0 on Wednesday to wrap up an unbeaten Champions League group phase, and are unbeaten in 11 games in all competitions.

While striker Diego Costa's goals have garnered much of the spotlight surrounding Atletico's success, coach Diego Simeone has quietly shown himself adept at managing his squad and whatever situation is thrown at him.

The former Argentina international has rebranded Atletico to replicate his own playing spell: committed, hard-working and selfless.

"What makes me happiest is that even when we rotate the players, including youngsters who are pushing for more minutes, that whether the team plays better or worse we always stay competitive," Simeone said. "That's the most important thing to maintain if we want to keep improving." Atletico host ninth-place Valencia on Sunday.

Cristiano Ronaldo showed no signs of rust in his return from a hamstring injury, scoring in Tuesday's 2-0 win at FC Copenhagen.

While the Portugal forward did have a penalty saved, he still managed to set a Champions League record with nine goals scored in group play.

Ronaldo is on pace for the best season of his career, with 26 goals scored in 19 games - not including the eight goals he's scored for Portugal since September.

"I played well, not my best, but I helped the team with a goal and by creating dangerous opportunities," Ronaldo said. "I'm very happy."

Ronaldo can expect a rude reception in Pamplona on Saturday, with Osasuna's Sadar Stadium always a hostile ground.

Midfield duo Luka Modric and Xabi Alonso are looking indispensable to Real Madrid's improving play.

Another standout Champions League performance from Modric has boosted his standing after he created an impressive long-range goal against Copenhagen that was similar to the one he scored at Manchester United last season.

Madrid coach Carlo Ancelotti has regularly deployed Modric alongside Alonso in midfield, with Madrid's play improving remarkably since the return of the Spain international.

Alonso's contract ends after the season, and Madrid seem reluctant to commit to the Basque player.

Madrid coach Carlo Ancelotti would prefer him to stay, however.

"I would like Xabi Alonso to sign a new deal as my Christmas present," Ancelotti said earlier this month. "He is a key player for Madrid."