Juan Martin del Potro stuns Novak Djokovic

It is no small task to steal the thunder from the current comeback kid of tennis, Rafael Nadal. But that’s exactly what a 6-foot-6 rocket launcher from Argentina did Saturday in the BNP Paribas Open at Indian Wells.

Argentina has had a great week. A new pope and now this.

Juan Martin del Potro won one of those matches that goes beyond compelling to spellbinding. When he beat Novak Djokovic in the late afternoon men’s semifinal, he did so in one of those tennis faceoffs that becomes edge-of-your-seat on every point.

The stage alone made this one a candidate for any book of tennis classics.

Nadal had just left the court, a 6-4, 7-5 winner over Tomas Berdych of the Czech Republic. The match had been competitive — nothing like what was to come — but Nadal’s story line overshadowed the forehands and backhands.

His appearance at Indian Wells marked his first on hard courts in nearly a year, 346 days to be exact. He pulled out of last year’s tournament in Miami because of a bad knee. He then spent seven months rehabbing and resting it at home in Spain, while the tennis world speculated on whether he might be, at age 26, finished.

That was huge in this sport, because he was wildly popular, and in the prime of his career had already won 11 major titles.

But he returned last month to some comfortable clay tournaments in South America, even won one of them, and came to the Southern California desert, a place where he has made the semifinals eight straight times and won twice. It was here that he would test the knee on the hard surface that dominates the tour and is the villain for his knee.

He got here and said he didn’t expect to win, which made his march to the final, including a straight-set victory over Roger Federer, so surprising.

“This is completely unexpected,” he said.

So was what happened next.

Djokovic is ranked No. 1 and has been for the last two years. He won this year’s Australian Open for the third straight time, now has six major titles, and came into this match with a 21-match winning streak, including 17 this season. Like Nadal, he had won the Indian Wells title twice.

Del Potro, 24, is best remembered for beating Federer in the final of the 2009 U.S. Open. But he later badly injured his wrist, disappeared for a while and finished the 2010 season ranked No. 257.

Djokovic had continued to leave the impression that he would always find a way. And that impression gained traction when he broke Del Potro’s serve at 4-5 of the first set. An air of inevitability floated about.

Even when Del Potro’s huge forehand started pushing Djokovic farther and farther back in the second set and Del Potro won it, the inevitability remained. Especially when Djokovic, fighting hard on each point, got it to 3-0 in the third set.

But each point was a toe-to-toe fistfight. Twenty-stroke baseline rallies became the norm. Each served big. Each returned the same.

The sellout crowd of 16,100 in the Indian Wells Tennis Garden felt the drama and turned up the volume. Djokovic helped that by asking them, with swinging arms, for more noise.

The temperature on the court hovered near 100 degrees. Shadows crept in, making 125-mph serves even more impossible to see, much less hit back. Every point brought gasps, murmurs, then ovations. Also, momentum changes.

De Potro, stationing himself well in his own backhand corner and, as Djokovic would say later, “inviting you to hit to his forehand side,” kept launching rockets. Djokovic, as quick and flexible as any player in the game, kept scampering and returning.

Del Potro got the break back and held serve at love for 3-3. Djokovic, battling heat, shadows, momentum and a grooved giant on the other side of the net, looked cooked but wasn’t. He somehow held for 4-3 but had to feel a different inevitability now, when Del Potro again held at love.

In Djokovic’s 4-4 service game, any break point would feel like, and basically be, a match point. And when Djokovic floated a backhand long after yet another long, tension-filled rally, Del Potro needed only to serve it out.

And he did so, with a classic flourish befitting a classic match. His 133-mph ace completed the 4-6, 6-4, 6-4 thriller, and the stadium rocked in appreciation.

Djokovic took it like a pro.

“It was his fighting spirit and my lack of concentration,” he said. “I didn’t deserve to win today.”

Del Potro, shaking his head at yet another papal question, finally caved.

“The pope comes, and then I beat [Andy] Murray and Novak,” he said. “There could be something there.”

His grin was as huge as his forehand. OK, nothing is quite that big.

bill.dwyre@latimes.com