For O'Neill, it was a point earned on the back of what had been an energy-sapping display in sweltering temperatures.
"We were very tired from about 65 minutes onwards, but that game will bring us on immensely," said O'Neill, who hopes to bring in some more new players ahead of the transfer deadline.
"We have not been able to get our squad up to strength and I knew coming here was going to be difficult.
"We ran out of energy towards the end and we hanging on, but at least we are off the mark."
O'Neill added: "We should have done better in the first half, James McClean had a shot and Jack Colback got himself into a good position too, but in the second half Arsenal had most of the possession and we had to defend."