Reilly Opelka scores his first five-set win over Stan Wawrinka at Wimbledon.

Reilly Opelka celebrates beating Stan Wawrinka, the No. 22 seed, on Wednesday at Wimbledon.

Reilly Opelka earned his second tour-level match win on Monday by beating Pablo Carreno Busta in Madrid.

Reilly Opelka reaches the second round of the Millennium Estoril Open on Monday.

Taylor Fritz and Reilly Opelka, two of five Americans seeded in Houston, visit local children in Highland Park.

Reilly Opelka celebrates a second-round win in Miami.

Reilly Opelka rallied from a set down three times this week to win the New York Open.

Reilly Opelka rifles 43 aces against Brayden Schnur to win his first ATP Tour title at the New York Open.

Reilly Opelka hammers 156 aces in his five matches at the New York Open for his first ATP Tour title.

Reilly Opelka wins an epic New York Open final over Brayden Schnur for his first ATP Tour title.

Reilly Opelka hits 43 aces on Saturday evening en route to victory against John Isner in the New York Open semi-finals.

Reilly Opelka serves up an impressive comeback against John Isner to reach his first ATP Tour final at the New York Open.

Reilly Opelka will go for his second ATP Tour semi-final this week in New York.

Reilly Opelka fights back from a set down to defeat Adrian Mannarino on Tuesday at the New York Open.

Reilly Opelka defeats John Isner in four sets at the Australian Open on Monday.

Reilly Opelka is the champion in Champaign, surging into the Top 100 of the ATP Rankings.

Reilly Opelka claims his second ATP Challenger Tour title of the year, prevailing in Knoxville.

Reilly Opelka throws out the first pitch at the Chicago White Sox game, during the Oracle Challenger Series Chicago.

Reilly Opelka throws out the first pitch at the Chicago White Sox game.

Reilly Opelka throws out the first pitch at the Chicago White Sox game.

Reilly Opelka is looking to make his second Grand Slam appearance in Paris.

Thumbs up from Reilly Opelka, who triumphed in Bordeaux for his first clay-court crown.

Reilly Opelka reigns in Bordeaux, claiming his first clay-court title.

Reilly Opelka kicks off his clay-court campaign with a semi-final appearance at the Sarasota Open.

From left to right: #NextGenATP players Andrey Rublev, Taylor Fritz, Alex de Minaur, Stefanos Tsitsipas and Reilly Opelka participate in a question-and-answer session on Tuesday in Indian Wells.