Leg spinner Devendra Bishoo claimed four wickets on his debut to help West Indies skittle Pakistan for 160 on the second day of the first Test on Friday.
Some of Bishoo's excellent work was undone though when the home team slumped to 34 for two in their second innings at the close, a lead of 100 runs.
Devon Smith, whose place is likely to be questioned again, fell to Mohammad Hafeez's spin, when the opener was trapped lbw for one playing a feeble stroke.
Pakistan then struck again when left-hander Darren Bravo was trapped leg before for eight by Saeed Ajmal.
Earlier, the Guyanese crowd was cheered by the exploits of the local spinner.
Bishoo picked his maiden Test wicket when he trapped Misbah-ul-Haq lbw for two with a flipper, a delivery that highlighted his diverse repertoire.
Asad Shafiq also went leg before to Bishoo for two, after a West Indies review, and Mohammed Salman was dismissed for four in similar fashion following a straight ball from the spinner.
Captain Darren Sammy chipped in with two wickets as West Indies, who were bowled out for 226 in their first innings at the start of the day, put the tourists under pressure.
The 25-year-old Bishoo, composed, confident and showing no sign of nerves, struck again when he had Umar Akmal caught behind for 33 as he finished with four for 68 from 25 overs.
"He has shown he is an intelligent bowler," said West Indies coach Ottis Gibson.
"He showed he has the ability to handle himself when he's put under pressure and that's a very good sign," he added.
"He only had 226 to bowl at but he didn't show any nerves. He has been very adaptable and handled the situation very well.
"Umar Akmal came at him quite hard and he responded very well. He varied his pace and demonstrated he knows exactly what he's doing."
Pakistan's total would have been even worse but for an unbeaten 40 by Abdur Rehman.
Seamer Ravi Rampaul also returned figures of three for 27 to cap a good all-round performance in the field from West Indies.
Now they need a big innings from their batting hope -- Lendl Simmons (18 not out) -- and some of the stability in the middle order that has been missing in recent performances.
But Pakistan also have plenty of spin options and will fancy their chances of dismissing the hosts cheaply to set themselves an achievable target.
Scorecard
West Indies (1st innings):(overnight 209-9):
D. Smith b Mohammad Hafeez 13
L. Simmons lbw b Saeed Ajmal 49
Darren Bravo lbw b Wahab Riaz 25
R. Sarwan c Mohammad Salman b Abdur Rehman 23
S. Chanderpaul b Saeed Ajmal 27
B. Nash lbw b Saeed Ajmal 5
C. Baugh lbw b Saeed Ajmal 4
D. Sammy c Umar Akmal b Abdur Rehman 12
K. Roach c Azhar Ali b Saeed Ajmal 24
R. Rampaul lbw b Mohammad Hafeez 14
D. Bishoo not out 15
Extras: (b5, lb7, w1, nb2) 15
Total: (all out) 226
Fall of wickets: 1-15 (Smith), 2-71 (Bravo), 3-127 (Sarwan), 4-136 (Nash), 5-142 (Baugh), 6-159 (Sammy), 7-162 (Chanderpaul), 8-175 (Simmons), 9-198 (Rampaul), 10-226 (Roach)
Bowling: Umar Gul 13-0-40-0; Mohammad Hafeez 13-5-22-2; Abdur Rehman 29-11-51-2; Saeed Ajmal 33-14-69-5; Wahab Riaz 10-1-32-1 (nb2, w1).
Overs: 98
Pakistan (1st innings):
Mohammad Hafeez b Rampaul 4
Taufeeq Umar lbw b Sammy 19
Azhar Ali b Sammy 34
Misbah-ul-Haq lbw b Bishoo 2
Asad Shafiq lbw b Bishoo 2
Umar Akmal c Baugh b Bishoo 33
Mohammad Salman lbw b Bishoo 4
Abdur Rehman not out 40
Umar Gul c Baugh b Rampaul 5
Saeed Ajmal lbw b Rampaul 1
Wahab Riaz c Baugh b Roach 5
Extras: (b6, lb3, nb2) 11
Total: (all out) 160
Fall of wickets: 1-5 (Mohammad Hafeez), 2-57 (Taufeeq Umar), 3-60 (Misbah-ul-Haq), 4-62 (Azhar Ali), 5-66 (Asad Shafiq), 6-80 (Mohammad Salman), 7-130 (Umar Akmal), 8-135 (Umar Gul), 9-141 (Saeed Ajmal), 10-160 (Wahab Riaz)
Bowling: Roach 10.4-2-40-1 (nb2); Rampaul 17-5-27-3; Sammy 12-6-16-2; Bishoo 25-6-68-4.
Overs: 64.4
West Indies (2nd innings):
D. Smith lbw b Mohammad Hafeez 1
L. Simmons not out 18
Darreb Bravo lbw b Saeed Ajmal 8
K. Roach not out 3
Extras: (b4) 4
Total: (2 wkts) 34
Fall of wickets: 1-3 (Smith), 2-23 (Bravo)
Bowling: Umar Gul 3-0-10-0; Mohammad Hafeez 3-1-5-1; Abdur Rehman 2-0-9-0; Saeed Ajmal 2-1-3-1; Wahab Riaz 0.5-0-3-0
Overs: 10.5
