Pakistan reached lunch on 2-67 on Saturday after Ireland had a first ball in Test cricket to remember in Dublin.
Delivered by Middlesex bowler Tim Murtagh, Pakistan opener Azhar Ali took a single off it but in the process, opening partner Iman ul-Haq was injured.
Diving to make his crease as Tyrone Kane tried to throw down the stumps, Imam - nephew of Pakistan great Inzamam - collided with the onrushing wicketkeeper Niall O'Brien.
After a brief delay Imam was able to carry on, with no wicket lost.
Ireland gave Pakistan a scare once play got fully underway on day two of the inaugural one-off Test in the grounds of Malahide Castle, just north of Dublin.
Former England international Boyd Rankin (1-7 off seven overs) had the honour of taking Ireland's first-ever Test wicket with Azhar (4) edging him to second slip.
Imam (7) went the very next ball, to Murtagh, struck on the kneeroll and given out lbw to leave Pakistan at 2-13.
With Haris Sohail and Asad Shafiq at the crease, Pakistan rebuilt after being put into bat and did not lose another wicket before lunch.
The first session ended with Sohail having made 28 and Shafiq 22.
The opening day was completely wiped out by bad weather on Friday.
The Irish are the 11th nation to play the longest format of the game after the International Cricket Council awarded Ireland Test status in June last year.
