© Aaron M. Sprecher/US Clay

John Isner wins his eighth match in a row on Thursday in Houston.

Isner Leads Trio of Former Houston Champs

Top seed wins his 10th match of the season

A trio of former Huoston titlists took to the red dirt on Thursday, and all three advanced to the quarter-finals.

Top seed and 2013 champion John Isner claimed his eighth match in a row, winning 93 per cent of his first-serve points (28/30) to beat Switzerland's Henri Laaksonen 6-4, 6-2 in only 65 minutes at the Fayez Sarofim & Co. U.S. Men’s Clay Court Championship.

Isner, No. 9 in the ATP Rankings, is fresh off his maiden ATP World Tour Masters 1000 title at the Miami Open presented by Itau. The 32-year-old will next face countryman and defending champion Steve Johnson, who saved six of seven break points to beat #NextGenATP American Frances Tiafoe 6-3, 6-4.

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The sixth-seeded Johnson hit 12 aces and broke Tiafoe three times to reach his second quarter-final of 2018 (Delray Beach SF).

“It was windy today.. I just felt like things were going to go both ways, good and bad... You really can't let the little things affect you. I think I did a great job of that in the second set,” Johnson said.

Tiafoe's fellow #NextGenATP American Taylor Fritz had never beaten compatriot Ryan Harrison, losing to him last year at the ATP Challenger Tour event in Dallas and during qualifying at the 2016 Rolex Paris Masters.

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But the 20-year-old Fritz came back to win their first tour-level contest 3-6, 6-0, 6-3. Fritz won a higher percentage of his second serves than he did his first (68 to 63) and broke five times.

Fritz will next play third seed Jack Sock, who won his fourth match of the year 6-4, 6-4 against Argentina's Horacio Zeballos. Sock lost his first nine break points but later broke Zeballos two times to advance. 

“He was coming up with some amazing shots, some amazing serves on the break points,” Sock told the Tennis Channel. “But I felt like I was playing well, kept playing my style, aggressive, looking for forehands, obviously, and it was paying off.”

Sock won the Houston title in 2015, his first ATP World Tour singles crown, and is making his sixth consecutive visit to the River Oaks Country Club. He will try to win back-to-back matches for the first time this season against Fritz. Sock leads their FedEx ATP Head2Head series 2-0.

Isner now has 10 wins on the year. The top American had won only two matches before winning the Miami title earlier this month.

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