BARCELONA, Spain (AP) -- Lionel Messi netted two goals within 15 minutes of coming on as a substitute to give Barcelona a 4-2 comeback win over Real Betis on Sunday and push his team to the brink of the Spanish league title.
After his teammates had rallied back twice to level at 2-2, Messi went on in the 56th and four minutes later curled in a free kick to extend his record scoring streak to 21 straight league appearances.
The Argentina forward struck again in the 71st by polishing off a superb passing combination with Andres Iniesta and fellow goalscorer Alexis Sanchez to reach the 60-goal mark in all competitions for the second straight season.
"We know Messi is the best,'' Barcelona defender Gerard Pique said. "We know every time he comes on he will give us something.''
Barcelona leads by 11 points with four rounds to go and would clinch its 22nd domestic crown if defending champion Real Madrid drops points against Malaga on Wednesday.
Messi has been hampered for the past month by a right hamstring injury.
Since hurting his leg on April 2, the four-time world player of the year has missed four games- including Wednesday's stinging 3-0 loss to Bayern Munich that sealed its exit from the Champions League- and come off the bench in two more before Sunday's match.
Like last week's game at Athletic Bilbao, Messi looked fit enough as he again tilted the match in Barcelona's favor.
Messi's double gave took his league-leading goal tally to 46 for the season, and kept him on pace to beat his own record of 50 from the last campaign.
Elsewhere on Sunday, Real Zaragoza beat Rayo Vallecano 3-0 to escape the relegation zone, while Mallorca remained in last place after drawing 1-1 with Levante.
Sevilla, meanwhile, rolled to a 3-0 victory over Espanyol to move into eighth place and stay in the hunt for a Europa League berth.
Barcelona showed signs of still feeling the effects of its midweek defeat to Bayern that completed its 7-0 dismantling of the Catalan side over their two-leg semifinal.
Barcelona was sluggish at the start and in the second minute its defense was slow to react to an apparently routine high ball that bounced through to Dorlan Pabon, who expertly slotted it beyond goalkeeper Jose Pinto, playing for the injured Victor Valdes.
Whistles of frustration were immediately heard from the demanding Camp Nou crowd, and they combined with the drizzling rain to further damper the hosts' spirits just when they should have been trying to take a step toward the league title.
Barcelona was quick to react, and with Messi on the bench, it fell to playmaker Iniesta to unlock Betis' defense in the ninth when he picked out Alexis at the far post to nod in his cross.
Barcelona pressed for a second goal with David Villa squandering two good chances before Cristian Tello hit the crossbar.
But it was Betis that went ahead again- this time against the run of play- with Ruben Perez's unstoppable long strike from well outside the area that Pinto had no chance to keep out two minutes before halftime.
"Football was a little cruel with us in the first half,'' Pique said. "We created a lot of scoring opportunities while they scored on the two chances they had, but then it was kind to us in the second half.
"We are close to the title. The sooner it comes, the better.''
Messi started to warm up at the start of the second half to the relief of the home fans who cheered his presence on the sideline.
Seconds before coming off for Messi, Villa made up for his earlier misses by knocking Dani Alves' cross under goalie Adrian San Miguel with a header after Betis' defense has left him unmarked in the box.
Messi then took over in his 20th multi-goal game of the season.
He had touched the ball just once when he scored an exquisite free kick, bending a left-footed shot just inside the near corner of the goalframe that San Miguel did well to touch but couldn't turn away.
Messi almost hit with another free kick in the 69th, with the ball landing on the corner of the goalframe.
But his second goal soon came when Messi linked up with Iniesta, who flicked on a no-look pass to play Alexis free in the area. The Chile forward then unselfishly crossed for Messi to tap in and complete the kind of beautiful move that Barcelona is known for and few other teams are capable of performing.