Leao’s solitary strike in the 8th minute took AC Milan past city rivals Inter to the top of the Serie A table, although the Nerazzurri have a game in hand.
Signed from Lille in the summer of 2019, Leao is enjoying his best season yet in an AC Milan jersey.
His goal against Sampdoria took him to 10 goals across all competitions for the season, four more than he managed in his debut season at the San Siro and three better than last term.
The 22-year-old is also AC Milan’s joint top scorer this season alongside Olivier Giroud.
"I believe he can always do better, he must not be satisfied," Pioli said at his post-match news conference. "He has the qualities to reach the top of Europe and the world.
"He reminds me of Henry, but it is true that Rafa must be himself. Leao is an extraordinary player, but he mustn't rest on his laurels."
Milan are in the hunt for a first Serie A title since the 2010/2011 season but Pioli wants his charges to stay grounded.
"Our goal does not change," he added. "We printed last year's standings at the beginning of the season and our goal is to improve on the 79 points collected last season.
"We had a perfect week and I'm happy for the guys who really gave everything, playing with intensity and determination, which allowed us to achieve these results.
"We also know that the championship is still long: let's concentrate as we have always done to better prepare for the next match to get the best out of it."
