The 27-year-old, who struck unbeaten knocks of 40 and 70 in Mumbai, has overtaken compatriots Meg Lanning and Beth Mooney as well as India opener Smriti Mandhana to become the fourth Australian and 12th batter to top the women's T20I rankings.
The second match of the five-game series at DY Patil Sports Academy had it all as more than 400 runs were scored and the hosts snuck home after a thrilling climax that ended in a Super Over.
India's star opener Smriti Mandhana underlined the importance of setting challenging totals for opponents and said that the side needs to work on it after the team's thrilling Super Over win against Australia.
A match that ebbed and flowed saw a dramatic finish with the Women in Blue edging the Aussies in the second T20I to level the five-match series 1-1. India scored 20 runs in the Super Over while the Australian batters could only manage 16 runs.
The batting duo carried on from where they left off in the first match and once again proved to be a menace for the Indian bowling lineup, smashing blazing unbeaten half-centuries to take Australia to a challenging total. Mooney scored 82* off 54 balls while McGrath was unbeaten on 70 from 5
Australia registered a comprehensive nine-wicket victory over India after opener Beth Mooney decimated the Indian bowlers in the first T20I of the five-match series at the Dr DY Patil Sports Academy on Friday