Keanu Reeves’ character bravely triumphs over adversity in his new movie “The Matrix: Reloaded,” but the actor showed even more heroism in real life recently when he made a desperate dash to save the life of his beloved sister Kim.

The 38-year-old star had just returned to the United States from Australian post-production work on his blockbuster film when Kim — who is on the Italian island of Capri fighting deadly leukemia — called him and triggered a heart-stopping emergency.

“Keanu had arrived home after a grueling 14-hour flight from Sydney to Los Angeles when the phone rang and Kim was on the line,” said a family friend. “The two are very close and Keanu was happy to hear from her and catch up.

“But only a few minutes into the conversation, Kim dropped the phone and there was only silence. Keanu frantically tried to dial her back, but got a continual busy signal.”

After repeated attempts to reach his sister, the action hero sprang into action — grabbing a passport and his still-unpacked bags and heading for the airport!

He booked a seat on the next flight for Italy and put in an emergency call to police on Capri to ask them to check on Kim.

“He caught the flight not knowing whether or not his sister was O.K. — or even if the police had been successful in finding her,” the friend said. “When he arrived in Rome 15 hours later, he called Capri police who told him that they had found Kim unconscious on the floor by the phone and that she was now in the hospital.

“Keanu caught a connecting flight to the island and rushed to his sister’s bedside, finding her weak but alive.

His entire journey had taken Keanu almost 30 hours of flying time.”

Thanks to her brother’s selfless devotion, Kim pulled through and she’s now continuing her medical treatment in Paris.

“Kim is Keanu’s best friend and companion,” Keanu’s father Sam told The ENQUIRER. “Keanu would give his life’s blood for Kim and she would do the same for him.

“They have always been inseparable. For that I am very thankful.”