MELBOURNE, Australia — The end came all at once for Rafael Nadal, and then it happened slowly.
Down one set and on the ropes against Mackenzie McDonald in the second round of the Australian Open on Wednesday, Nadal injured his hip while chasing down a shot in the eighth game of the second set. His eyes, filled with concern, immediately turned to his coaches seated courtside at Rod Laver Arena. He then crouched in the corner to catch his breath. Moments later, he returned to continue, because for Nadal, the one thing worse than losing is quitting.
Knowing his day and his tournament were all but done, he watched two aces blaze by, bringing him to the brink of going down two-sets-to-love against McDonald, a 27-year-old American who has never cracked the top 40 in the world rankings. McDonald had played the match of his life for nearly two sets, then did what he needed to do to close out a 6-4, 6-4, 7-5 victory over an ailing Nadal, who hobbled around the court for nearly another hour like a wounded deer.
Nadal's injury came after McDonald, a former U.C.L.A. player, had spent more than 90 minutes pasting the lines with his shots when he needed to most. Nadal, the No. 1 seed, called for a trainer, left the court to receive medical treatment for what appeared to be an injury to his midsection, near his right hip, then returned and played on.
The 36-year-old Nadal struggled to move and chase after balls with the abandon that has always been the hallmark of his game. He could barely generate power from his backhand. He somehow stayed even with McDonald through the first 10 games of the second set, hobbling around, taking wild cuts to try to end points quickly. But McDonald put just enough shots out of Nadal's reach to break his serve in the 11th, then clinched the match when Nadal netted one last backhand return.
When it was over, Nadal left to a rousing ovation, taking an extra few moments to turn and wave to the crowd.
In a news conference 45 minutes later, the defending Australian Open champion said his disappointment was unimaginable, his voice cracking slightly as he spoke about suffering yet another injury in a career, despite all of its success, that has been filled with them.
"I can't say that I am not destroyed mentally this time because I would be lying," he said.