Littlejohn drilled home the spot-kick which was awarded after Katie McCabe was brought tumbling to the ground as she weaved her way through the Haiti defence.
Ireland should have won by a bigger margin given the amount of possession they enjoyed but they found the deep-lying Haiti defence difficult to break down and the bumpy surface made it tricky to control the ball, particularly in the final third.
Manager Sue Ronan made three changes to the team which started Sunday’s 0-3 defeat by USA in San Jose. Skipper Emma Byrne returned between the posts, Niamh Fahey came into midfield and Katie McCabe started on the wing.
From the beginning, Ireland took control of the game and moved the ball about well with Stephanie Roche almost scoring in the opening minute with a long range shot while Ruesha Littlejohn also went close on two occasions in the first ten minutes.
Ireland finally broke the deadline after 21 minutes when McCabe weaved her way into the box from the right and was brought down. From the resultant penalty Littlejohn drilled home the penalty for her fourth goal in 31 appearances.
More goals seemed inevitable at that stage but, despite all their possession, Ireland were unable to add to Littlejohn’s goal. They had chances, with Littlejohn and Russell both going close on two occasions before half-time, while after the break Stephanie Roche, Denise O’Sullivan and Littlejohn were all off target as Ireland searched in vain for the second goal that would have made life a little bit more comfortable at the end.
Two minutes into injury time, Ireland had a major scarce when Sherly Jeudy found herself one on one with Byrne but the Irish keeper drew on all her experience to narrow the angle and save the goalbound shot.
This was Ireland’s final match before they kick off their Euro 2017 qualifying campaign against Finland in September and manager Sue Ronan was happy to sign off with a victory.
“It was good to get a win although I am disappointed we didn’t win by more given the amount of possession we had and the number of chances we created,” said Ronan. “Conditions were difficult but we were patient and kept the ball well most of the time. We had a narrow escape at the end but Emma Byrne showed her experience with a great save. We now have a break until September when the Euro 2017 qualifiers start and I think this week’s experience will stand to us then.”
Republic of Ireland: Emma Byrne (C) (Arsenal); Aine O’Gorman (UCD Waves), Karen Duggan (UCD Waves), Megan Campbell (Florida State University), Meabh De Burca (Galway WFC); Ruesha Littlejohn (Celtic), Niamh Fahey (Chelsea), Denise O’Sullivan (Glasgow City); Julie Ann Russell (UCD Waves), Stephanie Roche (Houston Dash), Katie McCabe (Raheny United). Subs Used: Emma Beckett (Amazon Grimstad) for McCabe (68). Unused Subs: Ciara Grant (UCD Waves), Ciara Rossiter (Wexford Youths WAFC), Nicola Sinnott (Wexford Youths WAFC), Emma Hansberry (Castlebar Celtic), Niamh Reid Burke (Raheny United), Jessica Gleeson (Wexford Youths WAFC).