Sachsenpokal
Ahead of the 2012–13 season, Domaschke's contract in Kassel was not extended and he was initially without a club until the beginning of October 2012. He finally completed a trial training at hometown club RB Leipzig and was committed to the goalkeeper position due to injury problems. He signed a contract until the end of 2012. He made his competitive debut for RB Leipzig on 13 October 2012 in the Saxony Cup round of 16 against SV Einheit Kamenz. In January 2013, Domaschke's contract was initially extended to the end of the 2012–13 season, which was then further extended until June 2015. In the 2012–13 Regionalliga season, Domaschke played two league games for RB Leipzig and won promotion at the end of the season to the 3. Liga. In addition, he won the Saxony Cup with the club, where he was used in the round of 16 and quarter-finals.