Second seed Diego Schwartzman outplayed Germany qualifier Daniel Masur 6-2, 6-2 to move into the quarter-finals of the German Tennis Championships in Hamburg on Wednesday.
Masur, who collected his first tour level win of the season by defeating compatriot Maximilian Marterer in the previous round, looked far from comfortable as he won just 51 percent of points on his serve.
Schwartzman treated the crowd to a display of power hitting as the Argentine capitalised on two breaks of serve in each set to wrap up the victory.
Earlier in the day, Brazil's Thiago Monteiro rallied from a set down to overcome claycourt specialist Fernando Verdasco 3-6, 6-2, 7-5.
Eighth seed Verdasco converted an early break point to take the first set but fatigue crept into his game as he struggled to match his opponent in longer rallies.
At 6-5 down and serving to force a tiebreak, the Spaniard committed four unforced errors to concede defeat after two hours and 10 minutes of play.
World number 146 Monteiro will look to reach only his second semi-final of the season when he takes on Slovakia's Jozef Kovalik, who raced past German Rudolf Molleker 6-4, 6-0.
India's singles challenge ends at Atlanta Open with Ramanathan ouster
After the high of Hall of Fame Open, India's Ramkumar Ramanathan made a first round exit from the ATP Atlanata Open singles while veteran Leander Paes too was ousted from the US$748450 hard court tournament.
Ramkumar, who ended a runner-up at the Newport event last week, lost 4-6, 4-6 to American Taylor Fritz.
Prajnesh Gunneswaran has already lost his first round to Slovakia's Lukas Lacko, thus Indian challenge ended at the tournament.
In the doubles, Paes and his American partner James Cerretani lost their opener 5-7, 1-6 to American pair of Mike Bryan and Frances Tiafoe.
Purav Raja and Ken Skupski though had advanced to the quarter-finals with a 6-4, 6-3 win over Ricardas Berankis and Malek Jaziri. Top seeded Divij Sharan and Artem Sitak are up against Romen Arneodo and Jeremy Chardy.