Peter Sobotta has not tasted defeat since 2010. | Tim Leidecker/Sherdog.com

German submission ace Peter Sobotta and unbeaten Polish prospect Pawel Pawlak will square off when the UFC returns to Germany in May.First reported by GroundAndPound.de earlier this month, the welterweight matchup was confirmed Monday by the UFC’s U.K. branch. The fight will be part of a UFC Fight Night card on May 31 at Berlin’s O2 World, an event headlined by a middleweight duel between Gegard Mousasi and Mark Munoz Sobotta, 27, did not find success in his first Octagon run, dropping three consecutive decisions to Paul Taylor James Wilks and Amir Sadollah in 2009 and 2010. The Planet Eater Gym leader has not lost since then and enters his second UFC stint on a five-fight winning streak, with all five wins coming via first-round rear-naked choke.Gracie Barra Lodz representative Pawlak is undefeated through 10 bouts and has finished nine of his opponents. The 25-year-old had an active 2013, earning five victories, including one submission by way of the rare inverted triangle choke.