Abu Dhabi - Pakistan stretched their lead over West Indies to 455 runs at lunch on the fourth day of the second Test in Abu Dhabi on Monday.
At the break Pakistan were 227-2 in their second innings with Asad Shafiq (58) and Younis Khan (29) at the crease as West Indian bowlers managed just one wicket in the session.
Shafiq reached his 16th Test half century - second of the match - by gliding off-spinner Roston Chase to third man boundary.
Younis, who scored 127 in the first innings, has hit just one boundary during his 54-ball stay as Pakistan will look for quick runs in the post lunch session in their bid to take an unassailable 2-0 lead in the three-match series.
Pakistan won the first Test by 56 runs in Dubai, a day-night affair played with the pink ball.
Resuming at 114-1 Pakistan were unable to score quick runs as West Indian captain Jason Holder kept a tight field, with only five boundaries in the session.
Ali, who scored a career best 302 not out in Dubai, edged Miguel Cummins to slip where Holder took a sharp catch for the fast bowler's first wicket in the series.
Ali hit five boundaries during his 137-ball stay at the crease.
West Indies bowlers tried valiantly for more wickets but spurned a review when Holder trapped Younis in front of the wicket but television replays showed the ball was missing the stumps.
The third and final Test will be played in Sharjah from October 30.