Lionel Messi scored twice on Sunday as Barcelona trounced Real Sociedad 6-1 to keep the pressure on Atletico Madrid, who squeezed past Alaves thanks to a late penalty save from Jan Oblak.

Oblak's 86th-minute heroics ensured Luis Suarez's 500th career goal was enough for a 1-0 victory at the Wanda Metropolitano, meaning the gap at the top of La Liga remains at four points, with 10 games left to play.

But the contrast between Atletico's nervy win against 19th-placed Alaves and Barca's demolition of a Real Sociedad side with hopes of qualifying for Europe spoke volumes about where the momentum lies in the Spanish title race.

Atletico will hope Oblak's save can prove to be a turning point after a challenging few weeks, while the international break might offer Diego Simeone's side a chance to reset and refresh ahead of the run-in.

"There are games where you suffer but that's what makes football beautiful," said Oblak.

Simeone said: "Like all great teams, there is always one that scores a lot of goals and one that makes a lot of saves. They are both decisive players who make the team stronger."

Barcelona has hit its stride, its six goals against Real Sociedad no less than it deserved for a scintillating attacking display, and perhaps its best since Ronald Koeman took charge.

"The team has improved a lot recently," said Koeman. "We've gone a lot of games without losing in the league, which was the only way to get back in the fight for the title.

"But we're still behind Atleti, Real Madrid are stronger. We have to keep going to the end."

Messi breaks appearance record

Messi scored his 11th and 12 goals in his last 10 games and made it 16 in 12 this year. The 33-year-old has also now passed Xavi Hernandez's record of 767 Barcelona appearances, which he had equaled against Huesca Monday.

Messi did not plow a lone furrow at the Reale Arena, where Sergino Dest scored twice either side of half-time after Antoine Griezmann slammed in the opener.

Ousmane Dembele and Real Sociedad's Ander Barrenetxea – with arguably the goal of the night – both registered between Messi's double in the second half.

For Barcelona, it is a ninth consecutive away win in the league, with a club record 10th within its grasp if it beats Real Madrid in the Clasico on April 10.

Real Sociedad next play Basque rivals, Athletic Bilbao, in the postponed Copa del Rey final from last year on April 3.

Dest had already hit the crossbar when Messi set Jordi Alba free down the left and while Dembele's finish was saved, Griezmann was on hand to convert the rebound.

Marc-Andre ter Stegen had to rectify his own poor clearance by getting down low to deny Alexander Isak but Real Sociedad's resistance was brief.

Messi slipped in Dest to fire in and then Alba pulled back from the other side for the American to make it three.

Messi snuck in behind early in the second half, poking in Sergio Busquets' ball over the top before Dembele was allowed to glide through unchallenged, and impressively drove into the far corner.

Barrenetxea put his side on the scoreboard, and brilliantly, by nipping inside Frenkie de Jong and thundering a shot into the top corner but Messi had the last word, a crisp finish curling inside the near post.

Suarez strikes, again

Messi stays ahead of Suarez in the La Liga scoring charts, despite the Uruguayan's excellent finish nine minutes into the second half against Alaves.

Thomas Lemar turned the ball around the corner to Marcos Llorente, who fed Kieran Trippier racing down the right, and he curled a cross in on the run to the near post, where Suarez headed in.

But without a second goal, Alaves always had a chance and it was given a golden one after Stefan Savic was judged to have put an arm across Luis Rioja just inside the penalty area.

Joselu stepped up and struck it well to his left but Oblak read it right and, with his left foot still pinned to the line, sprung out and pushed the ball away.