The West Indies just did enough to see off Pakistan as they opened their Champions Trophy campaign with a two-wicket Group B win at The Oval.
Man-of-the-match Kemar Roach had Pakistan reeling at 15 for three and they were all out for 170.
Captain Misbah-ul-Haq hit a career-best 96 not out.
The West Indies suffered a collapse of their own before tailender Roach hit the winning boundary with more than nine overs remaining.
On the ground where they won the 2004 Champions Trophy, the West Indies slumped to 15 for two after giant left-arm quick Mohammad Irfan removed Johnson Charles and Darren Bravo.
Chris Gayle typically drove Irfan, world cricket's tallest player, for six, only to be bowled for 39 trying to slog off-spinner Saeed Ajmal.
Pakistan and West Indies are in the same group as India and South Africa, with only the top two sides going through to the semi-finals.
India beat the Proteas by 26 runs in the tournament opener in Cardiff on Thursday.
Pakistan next play South Africa at Edgbaston on June 10 with the West Indies facing India at The Oval on June 11.