The Spanish defender deftly dived to his right to deny Tammy Abraham’s penalty in the second half after diving low to his left to stop Theo Hernandez’s spot kick in the first half.
The 33-year-old De Gea, a former goalkeeper for Manchester United, joined the Italian team in August, and his performance proved crucial to the team’s 2-1 victory over Milan.
The hosts’ goals came from Yacine Adli and Albert Gudmundsson, with a goal from Christian Pulisic tying the score in between. Along with the Milan goalkeeper Mike Maignan saving Moise Kean’s penalty, Fiorentina manager Raffaele Palladino was sent off in the last moments of the match.
Napoli defeated Como 3-1 to maintain their strong early-season form and top spot in the Italian league thanks to a goal from Scott McTominay after 25 seconds.
For Antonio Conte’s club, Marcus Thuram’s hat-trick helped them defeat Torino 3-2. Romelu Lukaku also scored, and they are now two points ahead of Inter Milan in second place.
On Sunday, Juventus gave up their first goal of the year and was unexpectedly held to a 1-1 home tie by Cagliari.
Juventus had taken the lead thanks to a penalty kick in the first half from Dusan Vlahovic, but Razvan Marin leveled the score in the 88th minute.
Juventus, without Gleison Bremer, Nicolas Gonzalez, Arkadiusz Milik, and Timothy Weah, was forced to pay for a loss of intensity.