Published: 2019-11-19 02:42:31 BdST
Hazard left Chelsea to join Spanish giants Real Madrid at the start of the season, just before Lampard replaced Maurizio Sarri as manager at the west London club.
Lampard has steadied the ship at Chelsea after a difficult start, guiding them to six consecutive Premier League victories and level on points with second-placed Leicester City heading into the international break.
When asked if he was surprised by Lampard's instant impact at Chelsea, Hazard told reporters: "No, not at all.
"I know Frank as a player, not as a manager, but he's a great guy. He's showed already after four months that he can be one of the best managers in the world.
"The good thing is that they are playing with young players, young English players. For England it's good, for Chelsea it's good. They are lucky to have young players with quality."
Lampard was handed a squad with a two-window transfer ban, leading to more opportunities to English youngsters such as Mason Mount, Fikayo Tomori, Reece James and Tammy Abraham - Chelsea's top scorer in the league with 10 goals this season.
"I don't know (if the transfer ban has actually been good for Chelsea)," Hazard added. "Maybe with two or three more players, they would be first."