Becoming captain of he was part of Vice-Admiral John Byng's fleet which engaged the French at the Battle of Minorca. The admiral's flagship nearly rear-ended "Trident" when Durell ordered the top mainsails aback in an attempt to cover HMS "Intrepid" which was, at that time, severely damaged. According to Dudley Pope, it was Durell who disobeyed the fighting instructions to keep to the battle line. Promoted to commodore in January 1758, he took part in the Siege of Louisbourg in June and July 1758 and subsequent capture of the Fortress of Louisbourg in July 1758. Then in September 1759 he took part in the capture of Quebec.