Haase then landed his first ATP title at the Austrian Open in Kitzbühel. In the opening round, he led Potito Starace, 6–3, 2–0, before his opponent retired due to injury. In the second round, he defeated second seed Feliciano López in a rain-delayed match that spanned two days. Hours later on the same day, he beat Andreas Seppi in the quarterfinals. In the semifinals, he defeated qualifier João Souza. In the final, he came out on top against experienced clay-courter Albert Montañés.