After the Australian Open, he participated in the 2011 SAP Open in San Jose, where he was accepted into the main draw via protected ranking (PR). He reached the semifinals without dropping a set, however he lost to top seed Fernando Verdasco in straight sets. Del Potro's next scheduled tournament was the 2011 Regions Morgan Keegan Championships and the Cellular South Cup, where he was accepted into the main draw via wildcard. Here, he made his second consecutive ATP semifinal, where he lost to top seed, world No. 8, and eventual champion Andy Roddick. To continue preparing for his first ATP Masters event since 2009, del Potro entered the 2011 Delray Beach International Tennis Championships. He defeated Ričardas Berankis, Teymuraz Gabashvili, Kevin Anderson and second seed Mardy Fish, to advance to an ATP-level final stage of a tournament since 2009 at the Barclays World Tour Finals in London. In the final, he defeated an erratic Janko Tipsarević in two sets to get back in the winners circle.