After spending a nearly a season out on loan to Watford, Heiðar returned to QPR. After regaining his place in the starting XI, scoring 13 goals as Rangers won the Championship in the 2010/11 season including a late winner against London rivals Crystal Palace at Loftus Road. Heiðar featured regularly under Neil Warnock for QPR in the Premier League, Heiðar became a Rangers legend by scoring the winning goal from a penalty in a 1–0 victory against arch rivals Chelsea. This was QPR's first win over Chelsea in over 15 years.