Alexis Sanchez’s last gasp goal saw Barcelona rally deep in the second half to defeat Real Betis 4-2 at the Camp Nou.

After a quick start, Barcelona were forced to watch Betis comeback from two goals down, nearly stealing the match and ending Barcelona’s aspirations for a fourth consecutive La Liga title. But with less than 15 minutes remaining, Alexis Sanchez stepped up to become the hero, breaking the deadlock and keeping the title race alive.

With everything on the line the defending champions showed their mettle, besting a tenacious Betis side with pedigree, belief, and guts.

The Sevillanos came out of the gates firing, with Jorge Molina testing Valdes early at the near-post before Jose Antonio Dorado’s glancing header forced a fine reaction save from the goalkeeper just moments later.

The backline of Puyol, Mascherano and Abidal struggled throughout the match to contain the quick counter attacks of Betis, highlighting the principal concern with a three man defense: when the midfield doesn’t pressure well to retain possession, it allows the opponent to break in numbers against a thin defensive line.

But in the heat of their struggles Barcelona showed their efficiency in front of goal, going ahead on the first attack of the evening. Alexis collected the ball just outside the box before slipping in Fabregas with a clever through ball. The midfielder’s low strike was sent rattling off the post, rebounding directly to Xavi who, in his 400th La Liga appearance, slotted home into an open net to open the count.

In the blink of an eye it became a two-goal advantage, as Alexis streaked down the left flank, sending a low cross into the box for Messi to steer home from eight yards out, putting the Catalans ahead 2-0 in the 12th minute.

Having outscored opponents by an immaculate 41-0 at the Camp Nou this term and up two goals in the match, Barcelona took their foot off the gas, believing the game to be already won.

The mistake would come back to bite them, as Ruben Castro pulled a goal back for the visitors just before the break.

Valdes did well initially to redirect Molina to the touchline after being played in on goal, only for the forward to set up Salva Sevilla on the edge of the box. Sevilla’s mishit shot rolled inches past the outstretched leg of Busquets and into the path of Ruben Castro, who pushed it into the back of the net from six yards out, sending Betis into the half trailing just one goal.

Unable to correct their defensive errors from the first half, Barca were again punished in the 52nd minute when Santa Cruz leveled the match at two.

Poor cover on the wings allowed Betis to quickly break on the counter, with Santa Cruz robbing Iniesta and pushing it out wide to Molina. The striker drove into the area before playing it inside for the Paraguayan, who sent a curling shot past Valdes with power to even the score.

Referee Ignacio Iglesias Villanueva then denied the Catalans two penalties, one for a questionable handball in the area, and the second for a blatant foul committed by Jefferson Montero on Andres Iniesta. The midfielder turned the defender on the touchline before being tripped by the thigh-high outstretched leg of Montero inside the box. In addition to not awarding the penalty, Villanueva had the audacity to book Iniesta for diving, despite all replays proving the referee mistaken in his estimation.

Barca rallied after the call and began attacking with pace and purpose before the game was turned on its head in the 70th minute, as Mario was shown a second yellow for bringing down Messi just outside the box.

Reduced to ten men, manager Pepe Mel swapped defenders for strikers in an attempt to preserve the draw, but Betis would prove unable to resist the late Barcelona surge.

Messi had a good chance spurned by strong defending before Sanchez fired wide with an open header at the far post.

However, the Chilean would amend for his mistake one minute later, latching onto a clever chip by Xavi before firing a low strike underneath the glove of Espinosa Castro from 25 yards out to secure the game winner.

Messi added the final touch, converting a late penalty for a Jose Antonio Dorado handball with a powerful shot into the upper left corner, allowing Barca to emerge victorious 4-2.

It was a momentous match for several Barcelona icons, as Sergio Busquets, Pep Guardiola and Xavi Hernandez all celebrated milestone moments.

Busquets reached his 100th official game in La Liga play, celebrating the victory alongside team captain Xavi, disputing his 400th league game for the blaugrana.

With the win, Pep Guardiola has now reached 100 official victories as Barcelona’s head coach, making him the youngest manager ever to achieve 100 victories, while doing so in record-setting fashion, needing a mere 132 games to reach the century mark.

Ruben Castro’s first half goal broke a streak of nine consecutive La Liga games by Victor Valdes without conceding a goal at home. It also marks the first goal Barcelona have given up in the Camp Nou since September 13th against AC Milan in the Champions League.

With the victory, Barcelona now hold a +41 goal differential at home this term, outscoring opponents 43-2 in the process.

The team will now begin preparation for Wednesday’s Copa del Rey showdown with Real Madrid at the Santiago Bernabeu. This will mark the ninth clasico in the last 13 months, offering yet another measuring stick for the distance separating Guardiola’s Barcelona and Mourinho’s Madrid.

Stress, provocation, intrigue and entertainment lie ahead. Just remember to take deep breaths and enjoy the show.

Article written by Barcaloco contributor Anson Woodring.  Follow Anson on Twitter at @ansonwoodring.

Full match highlights:

Barcelona – Betis 4-2 Highlights HD 15.01.2012 by iNfRaS0NiC