Ansu Fati sent Barcelona up to second in Group E of the Champions League with the winner in Tuesday's 1-0 win at Dynamo Kiev.
The Catalans' maiden away victory of the season in all competitions allowed them to move above Benfica, after their 5-2 loss at Bayern Munich, who qualified for the last 16.
Home boss Mircea Lucescu dropped forward Benjamin Verbic for Denys Garmash as midfielder Serhiy Sydorchuk captained the side after scoring twice in Saturday's league win over FK Maiupol.
Temporary Barca coach Sergi Barjuan made three changes from the weekend's draw with Alaves as Fati started instead of Sergio Aguero.
Argentina striker Aguero is set to miss at least three months of action while his treatment for a heart problem is assessed.
The sides had scored just once between them in their opening three matches of this year's competition and the run continued during a slow first half.
The best opportunity before the interval fell to Barca's Nico Gonzalez but his header was blocked two metres from the Dynamo line by team-mate Memphis Depay.
The breakthrough came with 20 minutes left as teenager Fati scored his third goal of the season.
Oscar Mingueza fired a low cross into the Ukrainan box and Fati half-volleyed the ball into the top corner after a deflection.
Lucescu reacted quickly after the opener sending on Brazilian Vitinho for Garmash.
He then emptied his bench by the 81st minute which included bringing Verbic into the fray.
Barjuan, taking charge after the sacking of Ronald Koeman with ex-Barca captain Xavi Hernandez reportedly in line to replace the Dutchman, survived a late scare in the 89th minute.
Dynamo's Bogdan Lednev whipped in a corner but centre-back Illia Zabarnyi failed to threaten Marc-Andre ter Stegen with a side-footed effort
The Catalans held on as Fati celebrated by banging the floor near the substitutes bench in relief as referee Ovidiu Hategan blew the final whistle on just their sixth win of the season in all competitions.