Allen made it to his first ranking event final at the 2011 UK Championship by beating Adrian Gunnell, Ali Carter, Marco Fu and Ricky Walden. It was his first success in a ranking event semi-final, after having lost in all five prior attempts. In the final he played Judd Trump with whom he held a 2–1 advantage in the previous meetings between the pair. Allen opened up a 3–1 lead early in the best of 19 frames match, but subsequently lost the next seven frames to trail 3–8. However, such a deficit brought out the best in Allen as he won five of the next six frames, which included three centuries. The comeback was not quite completed though, as Trump secured the frame he required to take an 8–10 victory. Allen said after the final, "I knew it was going to be hard the way he was playing, he scores so heavy and so quickly and I didn't feel I was playing too bad but Judd played so well and it was hard to compete." Allen made five centuries during the tournament, the most of anyone in the event.