Answer
Watson was ranked world's No. 1 all-rounder for 120 consecutive weeks. He holds the record for being the longest-serving No. 1 T20I all-rounder in the world. He achieved the feat on 16 February 2012 and remained at the top of the ICC T20I rankings for a total of 120 weeks, which was broken by India's Ravindra Jadeja in 2018.