Still basking in its 3-0 win over Bayern Munich, Barcelona now needs to protect its lead in the Spanish league.
Barcelona leads Real Madrid by two points with three matches remaining, although the end of the season is now in doubt. On Wednesday, the Spanish soccer federation decided to suspend all league and Copa del Rey matches from May 16 in protest at a proposed law on the sale of television rights and the division of the income earned.
That could make this weekend's matches even more important.
With both coming off Champions League games, Barcelona will host Real Sociedad on Saturday while Madrid hosts Valencia later in the day.
Barcelona closed in on a spot in the Champions League final on Wednesday, getting a pair of goals from Lionel Messi in the 3-0 win over Bayern. Madrid lost 2-1 at Juventus on Tuesday.
Here are some things to know about this weekend's matches:
More Messi magic
All the talk in Barcelona on Thursday was about Messi's performance against Bayern.
The Argentina forward again showed why he is one of the best ever when he netted two goals to finally break through a defense Bayern coach Pep Guardiola had crafted to keep his former pupil in check.
Messi used a pinpoint strike to slot a shot between goalkeeper Manuel Neuer and the post to get the lead in the 77th minute. He bettered that three minutes later when a quick change of foot sent defender Jerome Boateng tumbling to the turf before he made it look easy as he chipped the ball over the Germany's world champion goalkeeper.
But Messi wasn't done until he set up Neymar to polish off the win in injury time.
''Getting the opener and establishing the lead was so difficult for us and then the others came so quickly afterward, all of which constituted a super result to take into the return leg,'' Messi said. ''It's precisely what we wanted to achieve.''
The last time Barcelona played Sociedad, a 1-0 win for David Moyes' club at Anoeta Stadium, almost led to the complete meltdown for the visitors.
That Jan. 4 defeat, coupled with Barcelona's failure to overturn FIFA's one-year transfer ban for violating rules regarding the transfer from youth players, started a chain reaction that included the firing of its sports director, president Josep Bartomeu calling for early elections, and speculation that coach Luis Enrique's job was at risk.
Instead of collapsing, that week marked the team's resurgence.
Luis Enrique quickly ended his lineup experiments and found his first-choice players, which have rolled off 27 wins to go with one draw and a single loss since.
While Messi's two goals won deserved praise, Cristiano Ronaldo's single goal in the loss at Juventus may prove just as valuable for Madrid because it gives it a lifeline for the second leg next Wednesday.
But first Madrid must focus on Valencia if it wants to stay in contention for a league title is has won just once in the previous six seasons.
Ronaldo scored three goals last week in a key 3-2 victory at Sevilla, and the Ballon d'Or holder has tallied 54 goals in 50 matches this season, barely edging Messi's 53 goals in 51 appearances.
Madrid's season also hinged on a Jan. 4 match.
Madrid arrived to that date on a Spanish record 22-win streak, and left Valencia's Mestalla Stadium with a 2-1 loss. That was followed by Atletico Madrid eliminating it from the Copa del Rey and more league setbacks to Atletico, Athletic Bilbao, Villarreal and Barcelona as it relinquished its lead.
Valencia has only lost one of its last 14 matches as it holds onto Spain's final Champions League berth.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)