FLUSHING MEADOWS, N.Y.—All James Blake could do was shake his head. He spun around the Arthur Ashe Stadium court Monday night, tossing his headband and every tennis ball in sight to the roaring U.S. Open crowd, and a dazed smile crept across his face.

Not that the Blake was surprised by his 4-6, 7-5, 6-2, 6-3 win over No. 19 seed Tommy Robredo of Spain. No, the former Harvard All-American—he went pro in 1999, after two years with the Crimson—had already proven himself capable of a big win on Saturday, when he knocked off No. 2 seed Rafael Nadal in three commanding sets.

But as he stood there in the Monday evening dusk, his first Grand Slam quarterfinal berth finally secured, he looked stunned.

“It seemed, somehow, surreal at the time,” he said an hour and a half later, as he calmly munched a muffin in the interview room.

Also surreal to Blake is the fact that his quarterfinal opponent tomorrow will be none other than Andre Agassi, whose U.S. Open escapades Blake recalls watching as a young boy.

“Back when he had those denim shorts,” Blake laughed. “He had the long hair and the earring.”

This is the 35-year-old Agassi’s 20th year in the New York tournament—Blake himself is only 25—and for all the adoration Agassi garners as the game’s elder statesman, there’s no denying that the feel-good-story of this Open belongs to the younger of the two.

In the last year Blake has contracted the zoster virus, broken his neck and watched his father die of cancer. Not only that, but he has to relive this disastrous period nearly every day—in the sympathetic utterances from the fans, the hushed analysis of the broadcasters, and even the interview room, where he is asked if comeback performances such as last night’s are indicative of a newer, more mature perspective on the game.

But he’ll tell you they are.

Robredo held a 6-4, 5-3 lead over the admittedly flat-footed Blake before the latter reminded himself that “being down a set and a break doesn’t mean anything.”

Simple as that. Blake has been through worse and bounced back.

“And once I realized I was in it, I started moving my feet a little bit,” he continued.

Enough, at least, to reel off four consecutive games, take the second set 7-5, and knot the overall score at 1-1.

The final two sets were more traditional Blakeian fare, full of blistering groundstrokes and opportunistic netplay—and as the American began to ooze confidence, the Spaniard tightened visibly.

Blake improved his first-serve percentage from 46 in the first set to 73 in the fourth, while Robredo continued to spray unforced errors at pivotal moments, out-blundering his opponent 46-30 in the category at match’s end.

“Most of my maturity and my different perspective comes from the last year,” Blake said, though he is also encouraged by his loyal cheering section, “The J-Block,” whose T-shirts and chants have become something of a sideshow on the grounds these days.

The J-Block will meet its match when Blake faces Agassi tomorrow. The crowd loves Blake, his youthful enthusiasm, his inspirational energy—but it also loves Agassi, the rebel-turned-family man and two-time U.S. Open champion.

And, said Blake, “it’s going to be a night match. People have a Heineken or two, and they get a little rambunctious.”

“[But] I’m never going to be angry with a New York crowd,” he added, laughing.

It’s a win-win situation, really. If he defeats Agassi, Blake will become the first African-American to reach the semifinals of the U.S. Open. In addition, on the most basic of levels, Blake will have won by his own skills and not conservative, defensive tactics.

“I want to go out there and find out how good I am playing my own game,” he said.

And Should he lose? He’ll tip his cap and go home proud. Losing to Andre Agassi in the U.S. Open quarterfinals—well, things could certainly be worse.

—Staff writer Rebecca A. Seesel can be reached at seesel@fas.harvard.edu.