Robert Lewandowski struck twice as Barcelona moved 15 points clear at the top of La Liga with a comfortable 4-0 win at Elche on Saturday.

The Polish forward has endured a small dip in form recently but was back to his lethal best to continue the Catalans' procession towards the title.

Ansu Fati also found the net for the first time since October in the league and Ferran Torres rounded out the comfortable win, as Xavi was able to play some reserve players ahead of Wednesday's Copa del Rey semi-final clash with Real Madrid.

Elche, playing under new coach Sebastian Beccacece for the first time, are bottom of the table and never seemed likely to trouble the runaway league leaders. Champions Madrid, second, host Real Valladolid on Sunday.

"We'll see what Madrid do tomorrow, (but) if we win our games, we will be champions," Eric Garcia told Movistar.

"The coach told us all at the start of the season, everyone is important.

"We have an important game on Wednesday and he was able to rest some players."

Barca coach Xavi took the chance to experiment by deploying Garcia in Sergio Busquets' usual pivot role, and made several other changes to his usual side.

Torres and Fati started on the flanks, the latter having made headlines this week after his father complained about the Barca number 10's lack of minutes.

"(Goals) always give confidence to the forwards, today it went perfectly," Xavi told Movistar.

"Two goals for Robert, one for Ferran, one for Ansu, and Ansu's work -- he ended up exhausted, that's the truth.

"Aside from the goal, that is very positive for him and his confidence, how he worked for the team, it's really important for me, and the goal is a consequence of his work and his talent.

"I'm especially happy for Ferran, Ansu, the players that maybe deserved goals, today they scored."

Lewandowski broke the deadlock after 20 minutes with his first goal in four league matches, scuffing a finish into the ground, with the ball looping over a defender and into the net.

The Polish international and the top goalscorer in the league grabbed his 16th and 17th strikes of the campaign -- he has 27 across all competitions.

Barcelona should have increased their lead in the first half but Lewandowski nodded over from Torres' cross from just six yards out, while Elche defender Omar Mascarell slid in to clear a Jules Kounde effort off the line.

Gavi pulled the strings in midfield as Barcelona dominated at the Martinez Valero stadium, securing a 20th clean sheet of the season in the top flight.

Fati stretched Barcelona's advantage 10 minutes into the second half, running from the halfway line with the Elche defence backing off, before drilling into the bottom corner.

Lewandowski pounced again after Gavi won the ball back for the third and then played a fine long ball to Torres, who drifted inside and slotted home the fourth.

Xavi handed midfielder Aleix Garrido, 19, his debut in the final stages, as the hosts showed a few signs of life.

Fidel Chaves headed against the crossbar but like so many other sides this season, Elche could not beat Marc-Andre ter Stegen, with the German goalkeeper denying Josan Fernandez.

Elche are 14 points from safety with 11 matches remaining.