Robert Lewandowski's late penalty was enough for Barcelona to earn a slim 2-1 win at Osasuna on Sunday evening and stay two points behind Real Madrid in La Liga heading into the international break.
Portuguese pair Joao Cancelo and Joao Felix were both named in Xavi's squad after sealing late loan moves to Camp Nou but it was Kounde who made the first big impression of the contest when he rose highest to glance in Ilkay Gundogan's delivery.
The Catalan giants once again struggled to kill the match off and were pegged back when Argentinian winger Chimy Avila came infield and blasted a rocket past an unsighted Marc-Andre ter Stegen and in off the post.
However, Osasuna defender Alejandro Catena was sent off for grabbing Lewandowski in the box and the Polish striker cooly slotted in an 86th-minute winner.
How the game unfolded
Lewandowski had been vocally critical of Barca's lack of attacking threat during the opening weeks of the season but their intent could not be doubted in the first few minutes as they came ever so close to an opener.
A cross from Frenkie de Jong reached Gundogan whose attempted pass to Lewandowski was cleared back to De Jong. The Dutchman struck the right post and the rebound could only be turned wide by Lewandowski with the goal gaping.
16-year-old Lamine Yamal, handed a third league start of the season, saw a shot ricochet into Gundogan's path but the Germany international flashed his volley wide of the top corner.
The home side threatened next through Jose Arnaiz, who scored three Copa del Rey goals in three appearances for Barca in 2017/18, as the winger tested Ter Stegen with a decent crack from distance.
The pressure on the away goal continued to ramp up with Ter Stegen again required to keep Barca ahead. Jesus Areso broke into Barca's box and found Oroz, whose effort was met by an alert Ter Stegen who pushed the ball away from danger.
Osasuna deservedly levelled proceedings through a wonderful Avila effort. The winger carved a route towards the edge of the box before belting his strike in off the far post with Ter Stegen rooted to the spot.
Felix joined fellow loan arrival Cancelo for his debut off the bench late on as Barca searched for a winner that would eventually come from the penalty spot.
A ball over the top from De Jong found Lewandowski who entered into a tussle with Catena after controlling with his chest. The striker hit the deck and a penalty was awarded before VAR intervention saw the initial yellow card upgraded to a red.
Lewandowski, who struggled to influence proceedings for the most part of the game, stuttered and finished cooly as Barca saw out a lengthy amount of injury time with a player advantage to go up to third in La Liga, two points behind leaders Real Madrid.
Barcelona player ratings (4-3-3)
GK: Marc-Andre ter Stegen - 7/10 - Handful of important saves kept Barca ahead before Avila's strike from distance nestled in the far corner.
RB: Sergi Roberto - 6/10 - Pretty safe in possession and not all that forceful in defence before being replaced by Cancelo.
CB: Jules Kounde - 9/10 - Put Barca ahead with a perfectly-placed header just before half-time and was on hand to make seven clearances. Also won four of his six aerial duels.
CB: Andreas Christensen - 8/10 - Similarly dominant in the air, coming out of top in six of his seven duels. Completed 85 of his 89 attempted passes.
LB: Alejandro Balde - 7/10 - Had 83 touches with Barca targeting their attacks at Osasuna's right-hand side. Looked to dribble out of trouble and usually got it right.
CM: Ilkay Gundogan - 7/10 - Grabbed an assist for Kounde's header and made a number of forward bursts that would have resulted in goals on another day.
CM: Oriol Romeu - 7/10 - Made a joint game high of four tackles - alongside Gavi - and succeeded in his clear destroyer role.
CM: Frenkie de Jong - 7/10 - Barca's most involved player with 134 touches. Struck the post early on and did lose the ball three times but was otherwise joyous to watch.
RW: Lamine Yamal - 6/10 - Played just under an hour and one shot led to an opportunity for Gundogan.
ST: Robert Lewandowski - 7/10 - Struggled for clear-cut chances from open play and generally wasn't too involved, His effort to win the penalty and then convert ultimately pulled Barca to victory.
LW: Gavi - 7/10 - Typically pugnacious in defence, making five fouls and somehow escaping without a yellow card.
Substitutes
Joao Cancelo (59' for Roberto) - 6/10 - Showed off some of his trademark passing that will get the Camp Nou crowd cooing.
Ferran Torres (59' for Yamal) - 5/10 - Didn't see too much of the ball after coming on, getting only 15 touches.
Joao Felix (79' for Romeu) - 6/10 - Made his debut late on and seemed keen to put himself about.
Raphinha (90' for Lewandowski) - N/A
Inigo Martinez (90' for Christensen) - N/A
Manager
Xavi - 6/10 - Barca's clear dominance in possession isn't being rewarded with big scorelines like it has in the past. It nearly cost Xavi before Lewandowski won and converted a penalty.
