Joao Cancelo and Joao Felix made their Barcelona debuts as second-half substitutes as they edged out Osasuna for a dramatic La Liga win.
Jules Kounde scored the opening goal for the defending champions as he headed in from Ilkay Gundogan's corner at the end of the first half.
Chily Avila leathered in a lovely equaliser from the edge of the box.
But Robert Lewandowski scored a late winner from the penalty spot after he was fouled by Alejandro Catena.
Catena was initially booked, although it was upgraded to a red card by the video assistant referee.
Manchester City full-back Cancelo and Atletico Madrid forward Felix, both Portugal internationals, joined Barcelona on loan on deadline day.
It was a first La Liga appearance for 29-year-old Cancelo since his final Valencia game in August 2017.
Felix, who ended last season on loan at Chelsea, remains the third most expensive footballer ever after his £113m move from Benfica to Atletico in 2019.
Barcelona also brought on a third debutant, former Athletic Bilbao defender Inigo Martinez, late on.
They move onto 10 points from four games.
Meanwhile, Atletico's home match with Sevilla on Sunday was postponed because of torrential rain.
Several weather warnings have been issued across Spain as heavy rain causes major flooding across parts of the country with maximum red weather alerts in place in Madrid.
Latest Stories
-
Effutu MP commissions office for Hepatitis B; absorbs cost of testing, vaccination and management
3 mins -
Bawumia pushes for land digitisation to tackle land guard menace
9 mins -
Faith-based institutions are instrumental in national development – Bawumia
17 mins -
Upholding the Integrity of Presidential Promises: A call to Ghanaian leaders
25 mins -
I don’t start ‘beefs’; I only reply – Strongman refutes claims
28 mins -
Vice President Bawumia promises reforms to turn Ghana’s fortunes around
36 mins -
REGSEC warns encroachers along Tema-Sakumono Ramsar site as it races to prevent flooding
43 mins -
Kumasi International Airport to be commissioned ahead of time – Transport Ministry
51 mins -
Vomit your loot now or hold onto it and face the consequences – Asiedu Nketiah to Akufo-Addo, NPP
1 hour -
Democracy is going to reverse in West Africa if we don’t tackle economic hardships – Atuguba
2 hours -
Bawumia commissions 124 housing units for victims of Appiatse disaster
2 hours -
Stonebwoy’s The Livingstone Foundation surprises talented autistic boy with gifts
2 hours -
NPP should’ve referred Kingsley Nyarko’s bribery allegation to the police – Inusah Fuseini
2 hours -
Police pursue gunmen for killing 2 off-duty officers at Trasacco
3 hours -
Bayer Leverkusen beat Roma to win semifinal first leg
3 hours