Reuters - Sun, 14 Feb 19:41:00 2010
Mathew Tait scored the game's only try in the 46th minute and Jonny Wilkinson kicked England's other points, although the fly-half also missed three attempts at goal in a rare off day with the boot.
"The frustrating thing is that there were tries to score but we came away with just one," Johnson (pictured) said after his first away win since taking over the English national team.
"We did play good rugby at times but there wasn't a try at the end. When you play in Italy over here it's never easy.
"The guys are happy to have won. They know they could have done better."
Johnson was also unhappy at the indiscipline that allowed Italy penalties, which wing Mirco Bergamasco converted to bring them within two points of England, before Wilkinson sealed victory with a drop goal.
His pack's performance in the lineout was also a disappointment, after they dominated Wales in their 30-17 first round victory.
"For whatever reason, I think in the second half we lost five lineouts," he said.
"Our wide game was good, our counter-attack was good. We just didn't have the ball for long enough."
England's kicking from hand frequently looked aimless.
Johnson said the main problem was the failure to chase and put the receiver under pressure, rather than the kicking itself.
But he added: "There were times when we could have kept it in hand more. When we did, we looked good."
Italy coach Nick Mallett was pleased at the improvement shown after last week's 29-11 defeat in Ireland.
"They improved a lot in areas of the game we didn't do well in against Ireland, in particular our attacking play, the speed we moved the ball, and the lineout," he said.
"There wasn't a hell of a lot in the game
"It's a good thing the team are disappointed because before they would have been happy about coming so close against England.
"The next 18 months are very important for Italy to acquire confidence. If we continue to develop like this we can do great things at the World Cup next year."