Bender made his Bundesliga debut on 19 September 2009 in a game against Hannover 96. His biggest rival for the spot in the defensive midfield suffered several injuries and Bender established himself in the starting eleven very quickly. He scored his first Bundesliga goal on 12 February 2011 against 1. FC Kaiserslautern and extended his contract until 2017. The years 2011 and 2012 were very successful for Bender, as he was an important player in Borussia Dortmund's midfield and helped the team win the national championship in both years as well as the DFB-Pokal in 2012. On 6 January 2013, Bender extended his contract with Dortmund, keeping him at the club until 2017. During the 2012–13 season, he was struggling with several injuries which made Dortmund sign Nuri Şahin in January 2013. After treatment of his injury, Bender got another opponent for his position. He was on his way to becoming the number one player on his position and shared a place with team's captain Sebastian Kehl and helped the team to reach 2013 UEFA Champions League Final, although they were defeated by their domestic rivals Bayern Munich. On 27 July 2013, Bender won the 2013 DFL-Supercup with Dortmund 4–2 against Bayern Munich. In February 2014, he suffered injury after a loss against Hamburger SV, which eventually ruled him out for the rest season. On 21 February 2016, Bender signed a contract extension to keep him at the club until 2021.