FC Barcelona have won their maiden La Liga title under Xavi Hernandez, and a first for the club in four years, after beating cross-town rivals Espanyol away on Sunday evening in Spain.

The Catalans achieved this feat with four matchdays to spare, seeing off their opposition 4-2 at the RCDE Stadium with a first half brace from Lewandowski and a goal each by defenders Alejandro Balde and Jules Kounde.

At full time, Barca's players had to flee to safety down the tunnel as angry Espanyol fans invaded the pitch and tried to get at them.

The title win is a 27th Spanish top flight success for the Catalans, who are nine behind Real Madrid's 35 tally.

Barca will now go into the 2023/2024 season as defending champions, but their slump in the business end of the season after amassing a considerable points lead over other title race contenders highlighted a need to make reinforcements if they want to retain the title this time next year.

While their stingy defensive line has broken records and has conceded just 12 goals in 34 games, Barca are in need of cover at right back with usual central defender Kounde filling in at the position.

The already announced departure of captain Sergio Busquets also leaves a hole in defensive midfield, and the mixed form of Ferran Torres, Raphinha and Ansu Fati could see the trio sold this summer.

Xavi's 4-3-3 with four midfielders and Gavi as a false left winger only leaves space for one pure winger which will likely be Ousmane Dembele as president Joan Laporta tries to tie the Frenchman down to a contract extension until 2028 according to MARCA.

If Dembele becomes injured again, as he did at Girona in January which triggered a three-month absence, Barca will need to be able to count on other widemen to deliver from the flanks.

Striker Robert Lewandowski started the season in scintillating form after joining from Bayern Munich in a €50 million ($54.6 million) deal.

Though the Pole is still in line for the Pichichi gong given to Spain's top scorer, his form since returning from the World Cup and advanced years at 34 - soon to be 35 - mean it wouldn't hurt to to have back up on the front line.

One major obstacle in Barca making reinforcements of course is the need to shed €200 million ($219 million) from the wage bill to balance Financial Fair Play as publicly ordered by La Liga president Javier Tebas.

Yet Xavi's men and their fans should revel in their victory first, which will be celebrated together on Monday evening when the team takes a bus parade with the trophy through Barcelona city center.