The two teams had initially been due to lock horns on March 8, but the match was postponed shortly before kickoff following the tragic news that Barcelona's first-team doctor Carles Minarro Garcia had passed away.
There was controversy surrounding the date of the fixture off the back of an international break, but Barcelona swept aside any concerns to secure a routine three points, which has allowed them to open up a three-point advantage over second-placed Real Madrid.
Torres made the breakthrough in the 11th minute of the contest, before Olmo struck from the penalty spot 10 minutes later, and it then became three in the second period when Lewandowski came off the bench to register.
SPORTS MOLE'S VERDICT
Raphinha was missing for Barcelona due to his involvement for Brazil on Tuesday night, while leading goalscorer Lewandowski started on the bench before being introduced to score in the second period.
Barcelona also left centre-backs Ronald Araujo and Pau Cubarsi on the bench, with the latter nursing an ankle problem, but Hansi Flick's side still proved to be too strong for their opponents on home soil.
This was not a vintage performance from Barcelona, which feels strange to say considering that it was so comfortable, but it could go down as one of their most important of the season considering the circumstances surrounding the build-up.
Olmo's injury, which occurred shortly after he had scored from the penalty spot, will be a concern for Flick, but other than that, it was just about the perfect night, with a welcome clean sheet also being recorded.
Barcelona have the talent and experience to seriously challenge for a treble this season, and it is set to be a fascinating conclusion to the campaign for the team, who have now posted five straight wins in all competitions.
BARCELONA VS. OSASUNA HIGHLIGHTS
Ferran Torres goal vs. Osasuna (11th min, Barcelona 1-0 Osasuna)
Barcelona make the breakthrough in the 11th minute of the contest, and the goal comes from Torres, who turns a low cross from Alejandro Balde into the back of the net - Osasuna have been undone in the early exchanges here.
21st min: Barcelona 2-0 Osasuna (Dani Olmo)
Barcelona double their advantage in the 21st minute of the contest through Olmo, with the Spain international finding the back of the net from the penalty spot after Osasuna goalkeeper Sergio Herrera is penalised for a foul on the attacker.
The 26-year-old's first penalty was saved, but the referee ordered a retake after encroachment from the visitors, and he did not miss at the second time of asking.
77th min: Barcelona 3-0 Osasuna (Robert Lewandowski)
Barcelona score their third of the night in the 77th minute, and it is the substitute Lewandowski that gets his name on the scoresheet, with the experienced striker heading a cross from Fermin Lopez into the back of the net.
MAN OF THE MATCH - ALEJANDRO BALDE
In truth, this award could have been given to either Torres or Balde, as both players were excellent on Thursday evening and proved to be absolutely vital to Barcelona securing all three points, but it is the latter that just takes it.
Balde produced a wonderful cross for Torres to make the breakthrough, and the 21-year-old's overall performance was terrific, also boasting a pass success rate of 96%.
BARCELONA VS. OSASUNA MATCH STATS
Possession: Barcelona 74%-26% Osasuna
Shots: Barcelona 19-4 Osasuna
Shots on target: Barcelona 5-0 Osasuna
Corners: Barcelona 8-4 Osasuna
Fouls: Barcelona 7-14 Osasuna
BEST STATS
WHAT NEXT?
Barcelona will be back in action against Catalan rivals Girona on Sunday afternoon, before travelling to Atletico Madrid for the second leg of their Copa del Rey semi-final on April 2.
As for Osasuna, Vicente Moreno's side will be bidding to avoid a third straight loss in La Liga when they head to Athletic Bilbao on Sunday evening.
Written by
Matt Law