Nadal, Murray show toughness in reaching Rio semifinals

— -- The men's Rio Olympic semifinals are set, but none of the winners prevailed without significant resistance. Three of the four matches went the three-set distance and each lasted more than two hours.

Here's how they played out:

TOP HALF

Rafael Nadal def. Thomaz Bellucci 2-6, 6-4, 6-2

Rafa's confidence is soaring: He didn't look quite as dominant Friday, but as the match wore on, Nadal looked sharper and stronger -- signs that his championship mindset is back. It's been more than two years since Nadal has won a major. But the combination of his lethal groundstrokes and determined attitude not only bodes well for the rest of Rio, but the US Open as well.

Juan Martin del Potro def. Roberto Bautista Agut 7-5, 7-6 (4)

Del Potro more than a serve and forehand: In the opening round, del Potro stunned top-ranked Novak Djokovic in large part because of his electric forehand and serve. Against Bautista Agut, del Potro moved with precision around the court, socked backhands (his much weaker wing by comparison) and played stellar defense. Del Potro also won 46 percent of return points and broke his Spanish opponent five times. Hard to imagine a bigger fairy-tale ending to the Olympics than the 6-foot-7 Argentine, who has missed more than two years' worth of tennis because of reoccurring wrist injuries, hoisting gold.

BOTTOM HALF

Andy Murray def. Steve Johnson 6-0, 4-6, 7-6 (2)

Murray is Captain Clutch: Down a break in the third set against the American Johnson, Murray looked like he might become Rio's latest upset victim. But Murray broke back and eventually sent the match into a final-set tiebreaker, which he easily won. This performance came a day after the Scot fought back after losing eight straight games against Fabio Fognini to prevail. Murray is now two wins shy of winning his second straight gold medal in singles.

Kei Nishikori def. Gael Monfils 7-6 (4), 4-6, 7-6 (6)

Nishikori catches a big break: All the credit to the fourth seed for pulling off this miracle, but a game Monfils for most of the match gacked at the worst possible time. On the Frenchman's third match point, in the third-set tiebreaker, Monfils threw in a weak double fault to make it 6-6. Nishikori took the final two points to prevail. But this battle lasted 2 hours, 53 minutes, and Nishikori looked gassed. Although his semifinal opponent, Murray, was on the court north of two hours himself Friday.