He partnered home Favourite Ilija Bozoljac as they defeated Dustin Brown and Martin Slanar in straight sets 6–3, 6–3.

He partnered Evgeny Korolev of Kazakhstan but they lost in the first round in straight sets to the French duo Thierry Ascione and Laurent Recouderc 3–6, 5–7.

Then at Wimbledon he partnered Josh Goodall to the second round where they lost in straight sets to Mahesh Bhupathi and Max Mirnyi 3–6, 4–6, 4–6.

In January with now full-time partner Jonathan Marray, they won the Heilbronn Open Challenger defeating Frank Moser and David Škoch in straight sets 6–1, 6–4.

They next won the BH Telecom Indoors Challenger in March, defeating Yves Allegro and Andreas Beck in straight sets 7–6(7–4), 6–2.

Later that month, they won the Aegon GB Pro-Series Bath, defeating Yves Allegro and Andreas Beck in straight sets 6–3, 6–4.

In May, they won their fourth title of the year at the BNP Paribas Primrose Bordeaux, defeating French duo Julien Benneteau and Nicolas Mahut in straight sets 7–5, 6–3.

They won their fifth and final Challenger title of the year on home soil at the Aegon Pro-Series Loughborough, where they defeated Irish duo Sam Barry and Daniel Glancy in straight sets 6–2, 6–2.

The pair were defeated by fellow Brits and good friends Colin Fleming and Ross Hutchins in straight sets 4–6, 3–6.

At the 2012 US Open Delgado now with full-time partner Ken Skupski made it to the third round before losing to Spanish sixth seeds Marcel Granollers and Marc López in straight sets 2–6, 4–6.

[7] Since Gilles Müller finished 2013 at No 368 in the world rankings after missing the second half of the year with injury, he climbed back into the top 50.