The Italy international scored two goals in his side's 3-0 victory over Andrea Stramaccioni's men, with Colombia forward Luis Muriel also getting on the scoresheet
The Zebrette ran out comfortable winners thanks to two goals from the veteran striker and a Luis Muriel effort, while the Nerazzurri ended the game with 10 men following the dismissal of Juan Jesus.
“It was a vibrant game and in my view whoever took advantage of their positive moment would come out on top,” Guidolin told reporters after the game.
“These are two teams who play in fits and starts, so they can be extremely dangerous at any moment. Up until Di Natale’s goal, Inter had more chances, but they didn’t take them.
“In football these incidents are decisive and Di Natale was fantastic when scoring the opener. It is very satisfying to win this match, as the team worked well. Now we get closer to our objective.
“Was the red card decisive? We were already in the lead by that point and had turned the balance of the tie in our favour. I think the real key to the win was Di Natale’s first goal.”
Udinese sit in eighth spot in Serie A with 27 points following their victory, while Inter remain fourth.