Shinji Kagawa made Super Lig history on Sunday, becoming the first Japanese player to score in the Turkish top flight as Besiktas thrashed Antalyaspor.
Kagawa started Sunday's match on the bench before coming on to replace Adem Ljajic in the 81st minute.
Within a minute he had scored with his first shot on target, sending a low strike that beat goalkeeper Ruud Boffin, and two minutes later he had doubled his tally to complete an impressive debut.
Victory lifted Besiktas into third place in the table after 20 matches, although they remain 11 points behind leaders Istanbul Basaksehir.
Dortmund's sporting director Michael Zorc had some complimentary words about Kagawa when his departure was announced last week: "Shinji is not only an outstanding football player, but also a great friend of our club," he said. "We did not want to deny him this request."
Despite making the move to Turkey on deadline day, the Japan international said in November that he wants to play in Spain before he retires from football.
But for the remainder of the 2018-19 campaign Kagawa will be focused on helping his new club improve on their current third-place position in the Turkish top tier.