Andy Murray is making a habit of accomplishing things that hadn't been done in a while.

Or ever.

Murray became the first tennis player in Olympic history with two singles gold medals, winning his second in a row by wearing down Juan Martin del Potro of Argentina 7-5, 4-6, 6-2, 7-5 at the Rio de Janeiro Games in a final that lasted a tad more than 4 hours Sunday.

At the 2012 London Olympics, Murray won a singles gold and mixed doubles silver at the All England Club. That, of course, was also the site of his history-making Wimbledon championship in 2013, when he ended the hosts' 77-year wait for a British man to claim the trophy.

Murray won Wimbledon again last month, raising his Grand Slam title count to three.

The No. 2-seeded Murray took the final games after trailing 5-3 in the fourth set and stopped the resurgent run of the 141st-ranked del Potro, who knocked off No. 1 Novak Djokovic in the first round last weekend and No. 3 Rafael Nadal in the semifinals Saturday. No man ever has defeated the top three seeds on the way to a gold, but 2009 U.S. champion del Potro sure came close before winding up with a silver to go alonside his bronze from 2012.

Del Potro had the louder support, and one fan even yelled something as Murray was about to hit a shot while two points from victory. He put the ball in the net and glared in the direction the voice came from. Soon after, a fan wearing a shirt with Argentina's colors was escorted out.

Nadal, the 2008 gold medalist, lost 6-2, 6-7 (1), 6-3 earlier Sunday to Kei Nishikori, whose bronze is Japan's first Olympic tennis medal since 1920.

The final provided quite a contrast in styles: Murray's terrific returns, impenetrable defense and track-down-every-ball court coverage against the 6-foot-6 del Potro's booming serves and furious forehands. Both men are excellent at doing what they do, and it led to prolonged points. Not all were pretty, though, as they combined for 102 unforced errors, 85 winners.

When del Potro dumped a backhand into the net to end the match, Murray bowed his head and slumped his shoulders as he walked to the net, looking more relieved than thrilled. Del Potro trudged even more slowly forward, then pulled Murray in for a hug.

They were each on court for the fourth straight day, because rain washed out play Wednesday, leading organizers to eliminate the 24 hours of rest between the semifinals and final. Del Potro was the one who looked the worse for wear from the accumulated exertion.

He would have been the lowest-ranked man to be an Olympic tennis gold medalist and this would have been his first title at any tournament since January 2014. A couple of months later, he had the first of three operations on his left wrist that forced him to miss 2½ years' worth of Grand Slam tournaments. His first major tournament back was in June at Wimbledon and he still is not completely able to rip two-handed backhands the way he used to, often relying on righty slices.

By the 10th point of Sunday's match, a 26-stroke exchange that ended with Murray netting a forehand, del Potro already looked spent. He closed his eyes, rolled back his head, stuck out his tongue and sucked air. By the fourth game, del Potro was resting between points near the baseline, leaning forward with his elbows on his knees, catching his breath. By the fourth set, he was leaning on his racket as if it were a cane.