Goalscorer Megan Campbell explained the plan had been to test the Ghanaian keeper from long range.
“The keeper was short and we were under instructions to shoot from anywhere,” Campbell said after her latest dead-ball exploits.
With just five minutes played, Ireland were ahead courtesy of a sublime free-kick from dead-ball specialist, Megan Campbell leaving keeper Otoo stranded.
Ireland doubled their advantage in the 36th minute after Wilton’s Denise O’Sullivan’s pressure forced a mistake and the ball fell to Stacie Donnelly who stroked the ball into the roof of the net.
Ghana captain Sesu missed a penalty on 42 minutes, much to the relief of Noel King’s charges.
Ireland wrapped up the win in the 77th minute with a wonder strike from Aileen Gilroy from nearly 30 yards out on the right wing.
Ireland’s win means that the young ‘Girls in Green’ advance to the quarter-finals as group winners and will now meet Japan in the quarter-final on Friday.
REPUBLIC OF IRELAND: Grace Moloney, Ciara O’Brien, Megan Campbell, Jessica Gleeson, Jennifer Byrne, Ciara Grant, Aileen Gilroy (Hansberry 86), Dora Gorman (C), Denise O’Sullivan, Siobhán Killeen (Scott 75), Stacie Donnelly (Jarrett 69).