5 most economical 4-over T20 spells Mohammad Irfan went past 

#2 Chanaka Welegedara (4/2 against Tamil Union)

Welegedera picked up four wickets in his spell

Sri Lanka’s Chanaka Welegedera was as effective as the other two bowlers. In a fierce spell of bowling, playing for the Tamil Union, Welegedara affected two maiden overs while conceding one run each in the other two overs. However, he managed to pick up as many as four wickets in this game in 2015, two more than Morris.

The Sri Lankan bowled at an economy of 0.5 and equaled the record set by Morris for the most economical four over spell in T20 Cricket, although unarguably in a much weaker tournament.