Besiktas beat Antalyaspor 2-0 in the Gursel Aksel stadium in the Turkish Cup final to win the double.
Josef de Souza gave the Black Eagles the lead on 3 minutes before Rosier netted the second before the end of the first half.
The Black-Eagles ended up cruising to a comfortable victory to record their second piece of silverware inside a week.
Head coach Sergen Yalcin guided Besiktas to the league and cup double in his first season in charge of the club.
Yalcin previously played as a Besiktas player achieving cult status and was not expected to win silverware in his first season considering the financial state the club was in heading into the season.
The Black-Whites won their first double since 2008-09 in the process, the first Turkish Cup trophy since 2010-11 and first league title since 2016-17.
Besiktas will qualify for the Champions League next season as a result of winning the Super Lig.
Antalyaspor 0 – 2 Beşiktaş
Stadium: Gürsel Aksel
Referee: Ali Palabıyık, Ceyhun Sesigüzel, Serkan Olguncan
Antalyaspor: Boffin, Bünyamin Balcı (min. 70 Sam), Veysel Sarı, Naldo, Kudriashov, Gökdeniz Bayrakdar, Nuri Şahin (min. 78 Ufuk Akyol), Hakan Özmert (min. 46 Mert Yılmaz), Amilton (min. 78 Orgill), Fredy, Podolski
Beşiktaş: Utku Yuvakuran, Rosier, Welinton, Vida, Nsakala, Josef de Souza, Ghezzal (min. 86 Rıdvan Yılmaz), Hutchinson (min. 78 Mensah), Necip Uysal (min. 65 Dorukhan Toköz), Nkoudou (min 65 Gökhan Töre), Larin
Goals: min. 3 Josef de Souza, min. 30 Rosier (Beşiktaş)
Yellow Cards: min. 63 Nuri Şahin, min. 73 Kudriashov, min. 85 Naldo (Fraport TAV Antalyaspor), min. 87 Utku Yuvakuran (Beşiktaş)