Skipper Azhar Ali and Babar Azam both scored hundreds as Pakistan piled on the runs to build a huge lead over Sri Lanka in the second and final Test in Karachi on Sunday.
Azhar fell after scoring a return-to-form 118, his 16th Test hundred, while Azam reached 100 not out on the stroke of lunch for his fourth three-figure Test score as Pakistan stood at a mammoth 555-3 at the interval.
It was only the second time in a Test innings that the top four in the order had all scored centuries after openers Abid Ali (174) and Shan Masood (135) on Saturday. India against Bangladesh at Dhaka in 2007 was the only previous occasion.
Mohammad Rizwan was not out 21 with Pakistan leading by 475 with seven wickets in hand and five sessions to press for a 1-0 series win after the first Test ended in a draw due to bad weather in Rawalpindi.
Azam took a sharp single in the last over before lunch to complete his hundred in 164 minutes, his third in the last four Tests. He has so far hit seven boundaries and a six.
Earlier, when Pakistan resumed at 395-2 Azhar smashed three boundaries off pace bowler Vishwa Fernando and then took two runs to complete his first century in 12 months.
Azhar added 148 for the third wicket with Azam as Sri Lankan bowlers toiled on a National stadium pitch which has eased out for batting.
Azhar was finally stumped off spinner Lasith Embuldeniya after 11 boundaries in his 157-ball innings.
The Test series is the first in Pakistan since terrorist attacks on the Sri Lankan team bus suspended international cricket in the country in 2009.