Taylor Fritz made light work of his opener at the Washington Open as he earned a straight-sets victory over Aleksandar Vukic.
Fritz took just 60 minutes to see off the Australian 6-3 6-2 on Wednesday.
The American started strongly, racing into a 3-0 lead thanks to an early break which he converted at the second attempt.
Vukic attempted to force his way back into the set, but Fritz held onto his advantage, eventually getting over the line with his third set point.
Any hope of Vukic forcing a decider was quickly snuffed out as he dropped his first two service games in the second set, with Fritz winning the first four games in a row.
From there, he took little time to book his place in the last 16, setting up a meeting with Matteo Arnaldi.
Also in Washington, Daniil Medvedev fought back from a set down against Reilly Opelka to make it through to the next round.
Despite a shaky start, the Russian dug deep to earn a 3-6 7-5 6-1 victory in two hours.
Former Washington finalist Alex de Minaur is also through to the last 16, thanks to a straight-sets win over Yunchaokete Bu.
There was little to split the pair in the first set, but after edging a tie-break, he cruised through the second set to earn a 7-6 (7-5) 6-2 victory.
Data Debrief: Fritz on point
Fritz was in control from the very start and faced just one break point throughout the match, which he defended with ease.
He impressed on serve, winning 88% of his first-serve points (29/33) and struck 11 aces, while dropping only 10 points during his service games.
However, Fritz also converted three of four break points, which is ultimately what proved decisive.
