Henrikh Mkhitaryan, Borussia Dortmund's record signing, scored one goal and set up another during his first 45 minutes for the club as Dortmund beat FC Basel 3-1 in a friendly on Wednesday.
Mkhitaryan, 24, joined Dortmund from Shakhtar Donetsk in a €27 million deal on Tuesday.
And Dortmund sporting director Michael Zorc told kicker the Armenia international had enjoyed "a great debut", adding: "He instantly took on our game."
Goalkeeper Roman Weidenfeller was equally impressed, telling Ruhr Nachrichten: "We can be really delighted about Miki. I think we have signed a huge talent that will help us a lot this season."
Dortmund coach Jurgen Klopp handed debuts to his two other summer signings - defender Sokratis Papastathopoulos and striker Pierre-Emerick Aubemayang, who came close to scoring when his effort came back off a post.
Zorc said Dortmund's summer business was all but complete, adding: "We have strengthened the squad not in numbers, but in quality."
Dortmund will be without right-back Lukasz Piszczek, who underwent hip surgery in June, for the first half of the season, but Zorc said: "It would not make sense to sign someone for half a year."
Th Champions League runners-up have spent some €50 million in the transfer market and brought in more than €40 million for Mario Gotze, Leonardo Bittencourt, David Ginczek, Julian Koch, Lasse Sobiech and Moritz Leitner.