Carlos Alcaraz is growing from tennis’ future to its present right before our eyes at the U.S. Open. The 18-year-old Spaniard became the youngest male quarterfinalist at Flushing Meadows in the Open era, and he did it the hard way.

He earned it, by dominating Peter Gojowczyk in the fifth and final set, coming from behind in a 5-7, 6-1, 5-7, 6-2, 6-0 fourth-round win on Sunday.

“It’s a dream come true, no?” Alcaraz asked rhetorically. “It’s really tough to play these kind of matches, to play fifth sets. I hope to play more second weeks, to play more quarterfinals of Grand Slams. I didn’t expect to play quarterfinals here; so it’s a really good performance from me in these matches.”

After a five-set win over No. 3 Stefanos Tsitsipas in his previous match, the teen backed that up with a victory that made him the youngest man in a Grand Slam quarterfinal since an 18-year-old Michael Chang in the 1990 French Open. The El Palmar, Murcia native is the youngest here since Thomaz Koch 58 years ago.

“He is the next future, of course. He is so talented,” Gojowczyk, 32, said of Alcaraz. “I don’t know him so good, but we spoke a little bit. I think he was struggling too in the fourth set, but in the end he was pumped. Then he is going for it. And of course you are this high, 18 years old, you are young.

“Amazing player, good strokes from the baseline, first serve. He has a great future for him.”

The precocious Spaniard is pushing up that timeline.

Granted, this 3 ½-hour slugfest wasn’t always easy. And it was rarely clean, at least from Gojowczyk’s end. The German committed 84 unforced errors, 15 in the final set alone.

Gojowczyk had a dozen double faults to just three aces. Against one of the tour’s brighter young talents, that’s sloppiness the 141st-ranked qualifier could hardly afford.

After dropping the first set, Alcaraz broke right off the bat to set the tone for the second, taking it in just a half an hour.

Both players needed treatment on their left legs after Alcaraz held to go up 4-1 in the fourth. But the Spaniard took that set 6-2, and dominated the last 6-0. He’ll play Tuesday against No. 12 Felix Auger Aliassime.

“In first sets I thought I [had] reach my limit physically and mentally. The crowd was really, really important for me in this situation,” Alcaraz said. “I felt the energy of the crowd pushing me up. Without the crowd, it couldn’t be possible to be here.”