In the process, the 27-year-old from Lahore became the first batter in the history of ODI to score three consecutive hundreds on two separate occasions.
Babar Azam entered the match on the back of successive centuries against Australia in Lahore -- 114 and 105 not out. The Pakistan captain has now scored four centuries in five matches. Overall, he has 17 tons in 87 ODIs. He is also the current top-ranked ODI batter.
In 2016, the right-handed batter scored three successive centuries -- 120, 123 and 117 -- against the West Indies in the UAE.
During his 103-run knock off 107 balls, which featured nine fours, Babar Azam also broke Virat Kohli's record to become the fastest to score 1,000 runs as captain in ODIs.
Babar Azam reached the feat in the 13th innings as Pakistan captain. Virat Kohli reached the landmark in his 17th innings as India captain in 2017.
In his 13 innings as Pakistan captain, Babar Azam has scored 1005 runs at an average of 91.36 with a strike rate of 103.71. In this period, he has also scored six centuries and three half-centuries.
After the match, Babar Azam gave away his player of the match award to Khushdil Shah, who scored an unbeaten 41 off 23 balls in a stiff chase. The middle-order batter hit three successive sixes off Romario Shepherd in the 47th over to effectively turn the match in Pakistan's favour.
Babar, who made his ODI debut against Zimbabwe in 2015, is currently the world's top-ranked ODI batter. He has scored 4364 runs in 87 matches (85 innings) at an average of 59.78.
West Indies captain Nicholas Pooran won the toss and opted to bat first in sweltering Multan heat. Opener Shai Hope top-scored for the visitors with a 134-ball 127. Shamarh Brooks contributed with 70 off 83 balls.
For Pakistan, Imam-ul-Haq (65 off 71) and Mohammad Rizwan (59 off 61) hit half-centuries. Haris Rauf claimed four for 77 in his ten overs.
Both the remaining matches in the rescheduled series will be played at the same venue on June 10 and 12. The series is being telecast live on Sony Sports Network. Live streaming ofg the PAK vs WI series is available on SonyLiv.
The ODI series was postponed last December after a COVID-19 outbreak in the West Indies camp during the preceding T20 International series in Pakistan.