Wales centre Jamie Roberts blamed "silly mistakes" for their unconvincing 23-15 win over Italy at the Millennium Stadium in Cardiff.
First-half tries by wing Alex Cuthbert and Scott Williams underpinned a healthy 17-3 interval advantage but Wales needed Leigh Halfpenny's three penalties as Michele Campagnaro's second-half try double put the game back in the balance.
"We certainly made it hard for ourselves," Roberts told BBC One.
"We need a massive focus (next week against Ireland) on retaining the ball and no silly mistakes. We just have to look at ourselves in training this week and cut out the errors".
Coach Warren Gatland put a more positive spin on the result.
"They made it tough for us," he said. "Italy were dogged."
Gatland said his players felt the Italians were going down with injuries too much at the breakdown.
"It was a bit stop-start but that what we have got to deal with," he added.