6. 6/8 by Ajantha Mendis
It is the best bowling figures in T20I history. During the opening match of ICC World T20 2012 between Sri Lanka and Zimbabwe at Hambantota (18th September 2012), Sri Lankan mystery spinner Ajantha Mendis had the bowling figures of 4-2-8-6. That bowling performance helped them to bundle out Zimbabwe for just 100 (17.3 overs) in the second innings. Earlier, the hosts Sri Lanka scored 182/4 (20 overs).