Bellingham opened the scoring with an individual finish before turning provider for the second, heading a rebound off Málaga defender Carlos Puga and goalkeeper Alfonso Herrero and into his own net.
Across three LaLiga matches this season, the Englishman now has two goals and two assists, having been directly involved in both goals against Málaga after two injury-hit campaigns following his stellar debut season at the Bernabéu.
Freed from the shoulder problem that eventually required surgery and a run of muscular issues, Bellingham explained the tactical tweak behind his rediscovered sharpness.
"I'm a bit more free now, with freedom to drop deeper or push higher if we need it. I'm enjoying myself a lot, that's why I'm playing well," he said.
"It's always special, it's an honour to play for this club, in this stadium, with these fans. The ovation was lovely."
He was not entirely satisfied with the full 90 minutes, however.
"It's a great performance, but the last 20 minutes were really bad. I don't know why, but it wasn't good. We have a very strong squad, a great team with quality everywhere, and when the manager wants to change things, whoever didn't play the previous game is ready."
Mourinho has redesigned Real Madrid's shape specifically to get more out of Bellingham, playing him in a free attacking role behind Vinícius Júnior and Kylian Mbappé in a 4-2-3-1 rather than asking him to track back as auxiliary cover on the left. The manager made his admiration clear before kick-off.
"He's a unique player, hugely important for the team. He's a player with different talents, from the physical to the mental to the tactical. He also has the quality to win the ball back, to press, and to score goals with his aerial play. He's an absolutely impressive player," Mourinho said.
The numbers back up the sense of a rebirth. In his debut season, 2023-24, Bellingham scored 23 goals and added 13 assists as Real Madrid won the LaLiga and Champions League double, finishing second in the club's scoring charts behind only Vinícius.
Injuries then took their toll: his output fell to 15 goals and 12 assists in 2024-25, before collapsing further to just eight goals and four assists last season. On the evidence of the opening weeks of this campaign, Bellingham looks capable of matching those totals well before the end of September.