Scotland won six penalty corners in the opening six minutes of the game and finally converted one when Mackenzie deflected the ball past Lizzie Murphy.
Ireland were lucky to only be one goal behind but, from one of their rare forays into the Scottish circle, they equalised when Christina Hamill’s shot was saved, but Kealy pounced on the rebound.
Ireland were better in the second half and Kealy came close to scoring a second, but they wasted a couple of penalty corners chances and Watson’s superb strike, high into the net, put them on the back foot again.
Grundie said: “We’ve had a big push over the last year in terms of consistency, and the first half today was a big step backwards.
“We gave ourselves a job to do. Second half, we certainly improved and had opportunities, but we put ourselves under pressure with the first-half performance, which, as I say, wasn’t of the standard that we’d expect from ourselves.”
Irish captain Sarah Hawkshaw added: “I think we were definitely disappointed with our first-half performance. We were slow to get out of the blocks, for sure, and Scotland came at us really, really hard.
“They are a quality side, you know, there’s no doubt about that, but, it was a tired start to the game for us.
“We started to step out, gave ourselves opportunities. We probably needed winning a few more corners to give us more, with them being such a strength for us.”