US top seed John Isner blasted 20 aces Friday in defeating compatriot Dennis Novikov 6-4, 6-4, advancing to the ATP Hall of Fame Open semi-finals.
Isner, ranked 21st, never faced a break point in the 73-minute triumph to book a Saturday date against countryman Bjorn Fratangelo on the grass at Newport, Rhode Island.
"Just one of those matches on a surface like this, with two pretty good servers, that's how it can go – you just get one break and you try to hold onto it. That's what I did," Isner said.
"I felt like in the second set I could have extended it to a two-break lead but a lot of times one break is all I need so I'm happy to get off the court in pretty quick fashion so I'll be ready to go tomorrow."
Fratangelo, ranked 142nd, upset French fourth seed Pierre-Hugues Herbert 6-2, 5-7, 6-4 in Friday's other quarter-final match to book his first ATP meeting with Isner.
Fratangelo denied world number 72 Herbert on 9-of-11 break chances while the Frenchman could rescue only one chance from five before the American held at love to win after two hours and nine minutes.
Isner, the 2011 and 2012 Newport champion, seeks his 11th career ATP title and first since Atlanta in 2015. His most recent ATP final came at last November's Paris Masters, where he lost to Britain's top-ranked Andy Murray.
Australian 249th-ranked qualifier Matthew Ebden and Germany's 131st-ranked Peter Gojowczyk will meet in Saturday's other semi-final. It will be their first head-to-head meeting. Each seeks his first ATP singles title, as does Fratangelo.