Barcelona ground out a 1-0 win over Osasuna in La Liga on Wednesday as Xavi Hernandez started his long farewell as coach of the champions.
Atletico Madrid stay third, ahead of the fourth-place Catalans, after Memphis Depay snatched them a late 2-1 win over Rayo Vallecano.
Former Barcelona midfield great Xavi said he was stepping down at the end of the season after a heavy defeat last weekend left the Catalans 11 points behind league leaders Girona.
Barcelona cut that down to eight with a largely drab win over their mid-table visitors, earned by young Brazilian striker Vitor Roque's first goal for the club.
Osasuna had defender Unai Garcia sent off for two yellow cards but Barcelona could not put the game to bed.
The Catalans also trail second-place Real Madrid by seven points despite playing one extra match.
Xavi praised his players for the victory and said they reacted well after their painful 5-3 defeat by Villarreal last weekend.
"The dressing room has soul, we are a family, today we knew that we would react in a very positive way," said the coach.
Xavi said he was delighted for Roque after he struck his first goal for the club.
"I'm very happy for him, he had chances (in other games) but didn't take them, today it's come at last, his goal today is hugely positive," he added.
After leading Barcelona to La Liga glory last season, Xavi's team crumbled and in January were thrashed in the Spanish Super Cup final by Real Madrid and knocked out of the Copa del Rey.
Xavi insisted he would fight on to try and win La Liga and the Champions League, hoping his decision would change the team's dynamic but the first-half performance was as uninspired as any in his two-year tenure.
Ferran Torres limped off with a thigh injury in the first half to add to Barcelona's problems, with early reports suggesting he may miss the Champions League last 16 trip to Napoli on February 21.
Robert Lewandowski headed Barcelona's best chance wide in the first half.
After the break explosive 16-year-old winger Lamine Yamal, starting his fourth game in 11 days for Barca, swung in a superb cross which Gundogan sent narrowly wide.
It brought the chilly Olympic Stadium to life, with some fans chanting Xavi's name and the coach sent on Roque.
The 18-year-old, nicknamed Tigrinho -- little tiger -- was almost immediately on the scoresheet, netting with a smart header at the near post from Joao Cancelo's superb cross.
Roque's next involvement was to draw a foul from Garcia, who was dismissed for dragging the striker down.