By Guido Pizzorno Juventus have made it two victories in a row and moved up to second place in the Serie A table.
Man UtD won 4-0 at Juventus, the third consecutive game that the two sides have met.
The win puts the Dutch side on 11 points in the table and makes them three points clear of Inter in second.
Juventus are now only three points off second-placed Roma.
Juventus are in first place in Serie A and are one point clear of Napoli in second with 11 games to go.
Napoli are three points behind Roma and three points adrift of Lazio.
Juventus, who are unbeaten in their last 10 Serie A matches, have lost three straight away matches, with a win against Roma securing a 3-2 win at the Stadio Olimpico on Tuesday.
In a match that featured many defensive breakdowns, the hosts managed to hold on to take the lead at 1-1.
The goal came from a poor cross from the left wing, and the Juventus defence had a strong presence on the ball.
“We have a lot of players who are very talented, we just need to improve on the defensive line,” said De Guzmaso.
“I don�t know why it is that we are losing, but I know it is important to improve.
I think we need to be better.
I know the result is not going to be a game we like, but the players are happy to get a result.”
Juve defender Giorgio Chiellini added: “The goal was an obvious one.
We have had a lot more mistakes today than we did in the previous two games.
It was a mistake we have to correct.
However, the Bianconeri have been excellent all game and they have had no trouble defending.
A second goal from substitute Mario Mandzukic, in the 77th minute, put Juventus back on level terms with Roma.
After the match, Juve’s coach Guido Favero said: “I know we are not going into the game with the same spirit as we were at the beginning of the season.
It is not easy to play against a side who have had two consecutive defeats, but we have been working very hard to get back on track.”
The first half was an intense one, with both teams creating a lot in their attacks, and Juve dominated possession in both halves.
Pizzorno was the man who was instrumental in their first goal, when he put the ball over the line.
The goal came after an opening 10 minutes when Juventus defender Gianluigi Buffon was fouled by Buffon and the midfielder was unable to control the ball in his own half.
Buffon, who has not played in the league since April 2013, went down under a challenge from De Guzan.
He went down after the tackle and was helped to the ground.
Man Utd, meanwhile, looked to be in control of the match at first, but eventually the Biancons held firm.
Bastian Schweinsteiger was the target man in the second half for the home side, who scored two more in the final five minutes of the first half.
The German shot the ball home after De Guza had fouled the Italian defender, who then fell over.
But De Guzo put the game beyond doubt, as he made a spectacular stop to deny Schweinstein and his team-mate Mario Mandzi in the 72nd minute.
De Guza made his debut as a substitute in the 71st minute, coming on as a second-half substitute and making his first appearance for Juve.
Tiago Calvano was the next to make an appearance for Juventus in the 73rd minute.
The 25-year-old started the match and finished it as a late substitute, scoring the winning goal for the first time in the match.
At 1-0 down, Juventus were in complete control of possession, but a poor defending by Man Utddos side meant they were unable to put the match beyond doubt.
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