Teenager Christian Pulisic scored and created a goal as he replaced want-away Barcelona target Ousmane Dembele to spark Borussia Dortmund to a 3-0 win over Wolfsburg on Saturday.
The 20-year-old Dembele has attempted to force Dortmund into selling him to the Spanish giants by boycotting training and, having been suspended indefinitely, missed his side's opening game of the new German league season.
Dortmund's director of sport Michael Zorc confirmed Dembele will join Barcelona in this transfer window if they meet Borussia's asking price, reportedly set at 130 million euros ($152m).
"We have a clear position and a clear idea. If this idea is met, then he will transfer this summer," Zorc told Sky.
"Otherwise he will stay with us -- it's that simple."
Pulisic only turns 19 next month, but the US international superbly deputised for Dembele on the right wing.
He drilled home Dortmund's first goal on 23 minutes in a move involving Germany's World Cup-winner Mario Goetze, back after seven months out with a metabolic disorder.
"I'm feeling well again, but I am a long way off being 100 percent again," said Goetze.
"I have to train hard. There is still a lot of work to do."
Dortmund doubled their lead when ex-Barcelona defender Marc Bartra curled in a stunning strike on 27 minutes.
The centre-back, who was badly injured in the April bomb blast targeting the Dortmund team bus, celebrated by kissing the black armband that players on both teams were wearing in support of the victims of this week's Barcelona terror attack.
Pulisic then capped a brilliant display by putting Pierre-Emerick Aubameyang behind the Wolfsburg defence for the third goal on 60 minutes.
"I can only be happy with the game and the result," said new Dortmund coach Peter Bosz after his first Bundesliga game.
The Dutchman singled out Goetze for praise after the attacking midfielder played the first hour as he rebuilds his fitness after a long lay-off.
"It was obvious that Mario Goetze is an extraordinary player and will be very important for us," said Bosz.
"However, we must also be patient and I was glad he had collected a few minutes and did not hurt himself."
Dortmund top the fledgling table after defending champions Bayern Munich beat Bayer Leverkusen 3-1 on Friday through goals by new signings Niklas Suele and Corentin Tolisso, and a Robert Lewandowski penalty.
Australia international Mathew Leckie made a dream debut for Hertha Berlin at the Olympic Stadium by netting twice in a 2-0 win over newly-promoted Stuttgart.
Germany international Nicolai Muller suffered an embarrassing knee injury as he hurt himself while celebrating his winning goal for Hamburg against Augsburg just eight minutes into the 1-0 victory.
Hoffenheim bounced back from their mid-week defeat to Liverpool in the Champions League play-off first leg, prevailing 1-0 at home to Werder Bremen as ex-Leicester City striker Andrej Kramaric scored a late winner.
Hanover enjoyed a 1-0 win at Mainz on their return to the top flight as Martin Harnik scored the decisive goal on 73 minutes.
On Saturday night, RB Leipzig, who are in this season's Champions League group stages after finishing second last season, got off to a bad start by crashing to a 2-0 defeat at Schalke.
Nabil Bentaleb converted a penalty just before the break, then Yevhen Konoplyanka netted their second with a superb curling shot on 73 minutes to give Schalke's new coach Domenico Tedesco, 31, a winning start.
Tedesco pulled a surprise by dropping World Cup winner Benedikt Hoewedes from his line-up having also stripped the 29-year-old of the captaincy.