It was an important win for Madrid after they followed up their Clasico win with a goalless draw against Osasuna.
Speaking about Vinicius after the game, Ancelotti said: "I'll say again, I haven't done anything except pick him and give him confidence, which obviously he deserves because he's playing very well and scoring goals.
"As I've said many times I'm not a magician, I try to do well and give the maximum confidence to all the players... [Brazil] is a decision of my great friend, who's coach of Brazil, so nothing to say.
"Now he has confidence, everything is going well, he's getting used to playing more inside as well, because he has the pace to do it. Playing one-on-one on the wing is one thing and doing it in the middle is another, he's learning and doing very well."
Madrid were fortunate to be ahead at the break after Thibaut Courtois produced a number of fine saves to keep the score at 1-0.
Just after the hour mark, Guti was shown a second yellow card for a challenge on Toni Kroos.
The visitors doubled their lead nine minutes later when Luka Modric played through Vinicius to score his second of the day.
A mix up between Casemiro and Kroos saw substitute Milla grab a late goal for Elche but Madrid held on for the win.
"It's the work of the team, the work I've done since coming to Madrid, and now things are going well," Vinicius said. "I'm very happy and I want to keep going and helping the team until the end of the season.
"Sometimes we have to get behind the ball for a while, so that in the right moment we can score. Today it was difficult, it's important to be calm in attack and defence. Today we defended well, and we got in front of goal."