Despite being frustrated for large spells of the match, the Catalans found their breakthrough in the second half to go within three points of La Liga leaders Real Madrid.
Luis Suarez and Lionel Messi struck for Barcelona as they secured a vital 3-0 La Liga win at Osasuna on Saturday.
Luis Enrique's men entered the tie at El Sadar needing a win to end a streak of three successive draws that left them six points behind Real Madrid.
After being frustrated in the first half, the visitors managed to break through after the break when Suarez opened the scoring with an easy finish.
Messi, making his 550th appearance for Barcelona, then added the second and third goals to ensure the Spanish champions halved the deficit at the top of the table.
Barca had only lost one of their last 10 meetings with Osasuna in the top flight but their lack of ruthlessness in front of goal threatened to see them concede more ground in the title race, as Suarez and Messi both spurned good chances in a first half in which the visitors dominated.
Oriol Riera and Sergio Leon came close to breaking the deadlock for Joaquin Caparros's side, who offered stern resistance despite having claimed only seven points all season, but Messi combined brilliantly with Jordi Alba to allow Suarez to score against the 22nd different team in La Liga just before the hour mark.
Alba was again the provider as Messi turned in the full-back's cross, and a superb solo run and finish from the 29-year-old - his 17th goal in nine league games against Osasuna - capped the victory in injury time.
The win takes the champions back to within three points of leaders Madrid, who play Deportivo La Coruna later on Saturday, while Osasuna could now find themselves eight points adrift of safety by the end of matchday 14.
Suarez should have put Barcelona ahead in the eighth minute as he ran onto Messi's delightful clipped pass over the defence, but he placed a shot beyond Nauzet's right-hand post.
The Uruguayan came closer four minutes later, firing a shot onto the base of the opposite upright after he held off Miguel Flano 12 yards out, before Samuel Umtiti headed over the crossbar from an Andres Iniesta free-kick.
Barca's pressure was relentless but Messi became the latest to fluff his lines, with Nauzet sticking out a foot to deny the Argentine after Suarez set him free in the middle of the box, and the goalkeeper reacted brilliantly to tip Messi's chipped effort over the crossbar 10 minutes later.
Osasuna had barely managed a touch in Barca's half but they did fashion a glorious chance to take the lead before the break - Riera failing to connect with Miguel de las Cuevas' low cut-back as he slid in at the far post.
Sergio Leon had left Gerard Pique for dead with a sublime piece of skill in the first half, and he was inches away from humbling Marc-Andre ter Stegen early in the second when his brilliant chip from 30 yards came back off the crossbar with the Barca goalkeeper beaten.
Osasuna had shipped 29 goals in their opening 13 matches but were dealing comfortably with Barca's pressure - until a moment of brilliance from Messi carved them apart.
The Argentine feinted to shoot from 20 yards before sliding a superb pass through the defence and into the feet of Alba on the left of the area, and his square ball to Suarez - who was just onside - gave the striker a simple tap-in from six yards.
Osasuna looked deflated by the goal and any hopes of a result were dashed 18 minutes from time. Substitute Denis Suarez sent the untracked Alba clear down the left, and his low cross was steered into the far corner by Messi from close range.
Ter Stegen denied Sergio Leon with a good stop but Barca's victory was given some gloss in injury time, as Messi danced his way into the penalty area, dummied a shot to put Nauzet on the turf before lofting the ball beyond the goalkeeper and three covering defenders and into the corner of the net.
