The 22-year-old was inspirational in a dramatic 4-3 win at struggling Sunderland, scoring twice and setting up another for England international Frank Lampard as the Blues kept within four points of Premier League leaders Arsenal on Wednesday.
Doubts remain over Chelsea's long-term title hopes after their defensive frailties were again laid bare, but Mourinho preferred to concentrate on the positives after a third away league win of the season -- their ninth in succession at the Stadium of Light.
Hazard, the 32 million pounds (52 million pounds) former Lille midfielder, rightly earned the plaudits for his man-of-the-match display after taking his season's goal tally to eight.
"We played a phenomenal game, our best away performance this season, and we scored some beautiful goals," said Chelsea manager Mourinho.
"It's maybe the best performance I've seen from Eden in my time here. We know his talent, but the ambition from him from the first to the last minute, that for me was the first time I've really seen that.
"He has great talent and he's like a little kid out there enjoying himself. He was like that from the first minute and today the performance was fantastic," the Portuguese added.
Chelsea's other goal came when defender Phil Bardsley put through his own net while Mourinho's men conceded from three set-pieces, Jozy Altidore, John O'Shea and Bardsley profiting for a Sunderland side who remained bottom of the table.
Mourinho admitted his side needed to defend better, saying: "If Sunderland had two more corners late on, they could easily have won 5-4.
"It's about basics, and we failed in some of the basics. The most basic thing is defending set plays. We know the positions we must take in terms of defending spaces and men, and we failed in that.
"We should have won clearly, but we were at risk until the last second because we didn't. "When you play as well as we did, you should win comfortably, not end up giving the manager a headache like they did."
Only one side has avoided relegation after finding themselves bottom of the Premier League at Christmas, West Bromwich Albion managing to escape the dreaded drop nine years ago.
Sunderland have just three fixtures remaining to avoid propping up the rest of the division when the festive period kicks in later this month, but showed enough to suggest they have what it takes to extend their seven-season stay in the top flight.
"It's hard to be on the losing side, but we made Chelsea work very hard to come away with the three points," Gus Poyet, the Sunderland head coach and former Chelsea midfield player said.
"We couldn't do any more, but it wasn't quite enough. If we can fight like we did today on a regular basis, we can stay in the Premier League.
"We put in a massive effort and we have to make sure we concentrate on our recovery for the Tottenham game on Saturday."