But England roared back as another tourist, Owen Farrell, nailed a penalty before Danny Care's break away try put the hosts ahead.
Ireland threw everything at their hosts but could not breakdown their resolute defence and O'Connell admitted his side should have capitalised on their advantage, secured by Kearney's score.
"We mauled well when we chose to maul and we had control of the game at the start of the second half, but couldn't retain it," he said.
"We were well on top but we let them off the hook with a few silly errors, both defensively and how we tried to get out of our half.
"We put ourselves under pressure a few times and their belief went up."