The 18-year-old from Nangarhar then delivered an encore in his next over, sending two more West Indies batsmen packing with consecutive balls as the home team collapsed to 70 for six wickets.
Sri Lanka paceman Chaminda Vaas is the only bowler to take more than seven wickets in an ODI. He took eight for 19 against Zimbabwe in 2001.
West Indies eventually were dismissed for 149 after 44.4 overs, after Afghanistan had compiled 212 for six from their 50 overs.
Javed Ahmadi top scored for Afghanistan with 81, but the night belonged to Rashid, who dedicated his Man of the Match award to the victims of the recent Kabul bomb blast.
"We're trying our best to bring back smiles and happiness in whatever way we can," he said.
The Afghanistan victory comes on the heels of three straight Twenty20 losses to West Indies.
Friday's contest was the first of a three-match ODI series between the teams. The second game is on Sunday at the same venue.
(Reporting by Andrew Both in Cary, North Carolina; editing by Sudipto Ganguly)
