Ben Shelton: Zero to 149 mph in one second ... twice!

Bombs away.

Ben Shelton and his powerful serve continued to stun fans at the U.S. Open on Sunday as the 20-year-old American defeated 14th-seeded fellow American Tommy Paul, 6-4, 6-3, 4-6, 6-4.

Shelton broke his own feat for fastest serve at this U.S. Open when he fired two serves at 149 miles per hour in the same game of the third et. The serve was so jaw-dropping that even Paul applauded the first missile that Shelton fired past him in the fifth game of the third set.

It was such a stunning moment that Shelton seemed affected by the magnitude of it all and temporarily lost his focus. Yet, after being broken twice to lose the third set, he roared back to take the fourth and win the first match of his career against a top-20 player.

"Being at home here in front of an American crowd, I have felt the love all week. I played another American today and we had a great battle," Shelton said. "It is hard to believe I am playing on Arthur Ashe right now with the stands completely full."

With his 2-hour, 50-minute victory, Shelton has become the youngest American to advance to the last eight since a then-20 Andy Roddick did it in 2002. Roddick, it so happens, is credited with the fastest serve in U.S. Open history at 152 mph in 2004.

Shelton, in the quarterfinals Wednesday, will play American Frances Tiafoe, the No. 10 seed, who defeated wild card Rinky Hijikata, 6-4, 6-1, 6-4, later Sunday afternoon.

Shelton, a lefthander who is ranked 47th in the world, paused and flexed his biceps at the crowd after winning match point. It seemed an apt move to punctuate the match, which he controlled by winning 75% of his first-serve points and blasting 16 aces.

"I think it was straight adrenaline," he told the crowd after the match of his two 149-mph serves. "Any other atmosphere, I couldn't get it done. My arm would fall off.”

Shelton, who won two NCAA titles while being coached by his father at the University of Florida, turned pro last year and his star is rising fast. This will be his second Grand Slam quarterfinals this year. Coincidentally, he lost to Paul in his first, dropping a four-setter at the Australian Open.

Shelton believes he has grown as a competitor since then.

"I learned to be mentally tough," Shelton said after the match. "When I was playing in Australia after a long week, I was looking at my box, saying: 'My legs are dead, I am tired, I can't go anymore.' I realized how important it is to believe in myself. That I can go the full way emotionally and physically and now I have that belief here."

For the first time since 2005, three American men – Taylor Fritz, No. 10 Frances Tiafoe and Ben Shelton – are in the U.S. Open quarterfinals. In 2005, it was Agassi, James Blake and Robby Ginepri.

By Barbara Barker

barbara.barker@newsday.commeanbarb

Barbara Barker is an award-winning columnist and features writer in the sports department at Newsday. She has covered sports in New York for more than 20 years.