Pakistan will start Sunday looking to push towards a total past 400, and in Shadab and Ashraf, they look to have two talented young batsmen, although Shadab's leg-spin may yet be his biggest contribution to the match.
However, while Rankin and Tim Murtagh had troubled the Pakistan openers and runs had been hard to come by, after half an hour Ireland were still waiting for the breakthrough.
Rankin, the former England global and only Irish player with test experience, had the honor of Ireland's first test wicket when Azhar Ali (4) edged him to second slip in the eighth over.
Pakistan, sent into bat by Ireland captain William Porterfield, lost two wickets in successive balls to be 13 for two, but concerns that Ireland would pay for doing without a specialist spinner were eventually proved to be well-founded.
Fast bowler Boyd Rankin, who achieved his Test ambition for England in 2014 and returned to Ireland in 2016, is part of the golden generation of Irish cricketers who have been rewarded with places in the first Test squad.
Faheem Ashraf marked his Test debut with 61 not out and teenager Shadab Khan, in only his second match at this level, also hit a maiden Test fifty to be unbeaten on 52.
Brief scorecard: Pakistan 1st Innings 268/6, (Asad Shafiq 62, Shadab Khan 52 not out, Faheem Ashraf 61 not out).
Non-striker Imam, in scrambling to complete the run, found himself sandwiched between wicket-keeper Niall O'Brien and Tyrone Kane in a heavy collision.
Ireland's staggering 144-year wait for Test cricket was a memorable one to say the least after two Irish players smashed into Pakistan batsman Imam-ul-Haq in the opening ball of the match, leaving him dazed and confused on the floor.
Their partnership extended to 109, and Pakistan's to 268 for 6, before umpires had to call off play due to bad light.
Imam (7) went the very next ball, to Murtagh, struck on the kneeroll and given out lbw to leave Pakistan at 2-13. The duo added 58 runs for the third wicket to allay fears of an absolute collapse, but Sohail's fall only reignited the possibility.
Sohail (31) fell to a stunning low catch from Porterfield that gave Thompson his first Test wicket and left Pakistan 71 for 3.
Shafiq kept plugging away but, after Babar Azam (14) edged to second slip, he was finally dismissed, pulling to Andy Balbirnie. Pakistan captain Sarfraz Ahmed (20) was caught by Stirling in the slips off Thompson.