In 1973 he moved to the Staatsoper Dresden. On 21 April 1974, he took part in the world premiere of Rainer Kunad's "Sabellicus" at the Berlin State Opera. In Dresden he also sang the title role in Bartók's "Bluebeard's Castle" and as Moses in Schoenberg's "Moses and Aron", directed by Harry Kupfer. He sang leading roles in the world premieres of Udo Zimmermann's "Der Schuhu und die fliegende Prinzessin" on 30 December 1976 and Kunad's "Vincent" on 22 February 1979 in Dresden. In 1983, he performed the title role in Aribert Reimann's "Lear" at the Komische Oper Berlin. He moved to the opera house in 1984 together with Kupfer. Haseleu appeared as Holofernes in the world premiere of "Judith" by Siegfried Matthus on 28 September 1985 at Berlin State Opera. In 1988, he performed as Leporello in Alexander Dargomyzhsky's "The Stone Guest" at the Komische Oper. In 1998, he took part there in Henze's "König Hirsch".