Madrid host Chelsea at the Bernabeu on Wednesday in Lampard's second game back in charge at the club following his appointment last week until the end of the season.
Lampard opened his second spell with the club with a 1-0 loss at Wolves on Saturday but Ancelotti, who coached Lampard while Chelsea manager himself from 2009-11, said he expected his former player to do a "fantastic" job.
"I'm 63 and he's 44, so I have 20 more years experience than him, but that won't change what happens in the game," Ancelotti said in his prematch news conference. "Lampard was a really great player, I was lucky to coach him ... he was a fantastic, extraordinary professional.
"He knows what can happen in these games and how to prepare a team for these games. Experience doesn't mean much. He knows a lot of the players and he'll do well for sure."
Madrid and Chelsea will meet in the Champions League for the third time in as many seasons, with Chelsea coming out on top in the 2021 semifinals and Madrid victorious last year.
Chelsea are 11th in the Premier League after a difficult season which has seen the club sack coaches Thomas Tuchel and Graham Potter before turning to Lampard, who himself was dismissed by Everton earlier this season amid a relegation battle.
"I'm sad, yes," Ancelotti said, when asked about his former club's struggles. "I have fantastic memories of this club, the people who are still working there, I'm a Chelsea supporter of course.
"I had two good years there. [Would I] go back? No, I think and I hope Lampard is able to do a fantastic job with them."
"He looks fine," Ancelotti said. "He's trained well. We know him, he has extraordinary human qualities. I don't want to comment on what happened but tomorrow he'll give everything as always."