When lightning stopped play Pakistan were 268 for 6 and Shadab (52*) and Faheem (61*) were looking in control at the crease.
An expectant crowd of nearly 6,000 filled the temporary stands in anticipation of witnessing a piece of sporting history, with Tim Murtagh, the Middlesex seamer, delivering the historic first ball - and it wasn't without drama.
The ball had travelled just a couple of feet from the stumps and wicket-keeper Niall O'Brien and fielder Tyrone Kane both darted towards the ball while Ul-Haq, on Test debut, dived to make his ground.
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.
Pakistan's Imam-ul-Haq down injured. O'Reilly, who also works with Dublin's senior footballers, would not have expected to be dealing with an impact injury after the first ball.
With that, Rankin had captured the first-ever Test wicket for Ireland and wrote himself into the history books.
Rain washed out the whole of Friday's scheduled first day but a day later Malahide was bathed in sunshine, with grey clouds replaced by sunny blue skies as Ireland, from the moment of the toss, officially became the 11th nation to play men's Test cricket.
With Haris Sohail and Asad Shafiq at the crease, Pakistan rebuilt thereafter and would not lose another wicket before lunch.
Imam was leg before wicket for seven to a Murtagh delivery that came back into him.
Murtagh got the full treatment from his team-mates and there was nearly a third wicket next ball, but Stuart Thompson was wide of the stumps where a direct hit would have seen the end of Haris Sohail, who was well out of his crease backing up.
Murtagh got his second wicket after continuing his excellent line of attack, beating the bat on numerous occasions. The action on the sun-kissed day was a joy for the Irish supporters as the hosts made an outstanding with the ball, taking two wickets for just 13 runs in the match.
And when Pakistan captain Sarfraz Ahmed (20) was caught by Stirling in the slips off Thompson, the tourists were 159 for six in this stand-alone match.
The third's play will start at 11am on Sunday, with the umpires again adding time on later in the day.