Reigning Rio Open champion Dominic Thiem cruised through to the round of 16 on Tuesday, while Gael Monfils survived his first-round encounter.
Thiem – the second seed – accounted for Serbian Dusan Lajovic 6-2 7-5 on the clay courts in Rio de Janeiro.
Running hot after winning his second Argentina Open last week, Thiem continued his fine form on clay as he converted four of 11 break points.
Next up for the Austrian star is Pablo Andujar, who was too good for Gerald Melzer 7-5 6-2 at the ATP 500 tournament.
Entertaining Frenchman Monfils was forced to dig deep en route to the last 16 after saving a match point against Horacio Zeballos.
Zeballos led 5-2 in the third and deciding set and served for it at 5-3 but Monfils reeled off five successive games to triumph 7-5 3-6 7-5.
It does not get any easier for the unseeded Monfils – a semi-finalist at the Argentina Open.
Top seed and Australian Open runner-up Marin Cilic stands in the way of Monfils and a spot in the quarter-finals.
It was a good day for seeds, with Pablo Carreno Busta, Diego Schwartzman and Pablo Cuevas all progressing.
Spanish third seed Carreno Busta defeated Marco Cecchinato 6-4 6-1, Schwartzman – the sixth seed – was leading 4-1 when Casper Ruud retired, while seventh seed Cuevas outlasted wildcard Thiago Monteiro 6-7 (5-7) 7-6 (12-10) 6-3.
Federico Delbonis celebrated his 100th tour-level victory after Jiri Vesely retired down 6-2 3-2, Aljaz Bedene beat Andreas Haider-Maurer 7-5 6-0 and Nicolas Kicker topped Victor Estrella Burgos 6-3 6-3.
|Pogba: Kante, Matuidi have 15 lungs|
|Julian Nagelsmann: the Bundesliga prodigy swapping Hoffenheim for RB Leipzig|
|England dominate in Durham to close in on series whitewash|
|´Fortunate´ Federer closes in on Halle title|
|Calamity Caballero and Sampaoli tinkerings leave Argentina a broken mess|
|Wimbledon champion Muguruza confident despite Birmingham defeat|
|Argentina 0 Croatia 3: Caballero drops clanger as Messi´s men are stunned|
|Funes Mori departs Everton to join Villarreal|
|Djokovic beats Dimitrov as Kyrgios lays down a marker|
|Relegated Verona appoint World Cup winner Grosso|
|Trotz named Islanders´ new coach|
|Matic and Serbia ready for ´hellish´ Switzerland clash|
|Fleetwood flounders as Gros takes Pulheim lead|
|No attacks on Neymar, pledges Costa Rica boss Ramirez|
|Giroud return brings structure to France, but again they disappoint|
|Brighton sign Sunderland goalkeeper Steele|
|Schmeichel and Eriksen blast ´exceptionally harsh´ VAR penalty|
|Nigeria´s young World Cup squad learning on the job - Rohr|
|Moody: England players need protection|
|France 1 Peru 0: Mbappe books last-16 spot with record goal|
|I don´t need anyone to hold my hand - Verstappen|
|Captaincy comes back around to Silva as 2014 pain fades|
|We don´t want to be losers - Petkovic|
|Alba not interested in Barcelona exit as Tottenham rumours swirl|
|BREAKING NEWS: Nagelsmann to take RB Leipzig role in 2019|
|Messi cannot be compared to Maradona, claims Argentina World Cup winner Kempes|
|Mbappe sets France record with maiden World Cup strike|
|Federer comes through tough Halle test|
|Nagelsmann to leave Hoffenheim amid RB Leipzig rumours|
|Gerrard brings former Liverpool team-mate Flanagan to Rangers|
|Cipriani to be ´the calmest guy in the room´ on England return|
|C´est magnifique! Lloris earns 100th France cap|
|Belgium v Tunisia: Hazard hoping for World Cup lift off|
|WATCH: Manchester United ditch piano to welcome Fred the red|
|Hamann springs to defence of Ozil|
|Alonso non-committal on future after Le Mans triumph|
|McInally returns to Scotland starting line-up|
|Giroud & Matuidi start as Deschamps drops Dembele for Peru|
|Torreira focused on Uruguay amid Arsenal links|
|NBA Mock Draft 2018: Deandre Ayton leads intriguing first round|
|Tite will not take away Neymar´s ´genius´|
|Australia show promise but calls for Cahill ignored amid lack of cutting edge|
|Manchester United means greatness - Fred aiming for titles following Old Trafford switch|
|Denmark 1 Australia 1: Jedinak strikes back after Eriksen rocket|
|Neymar not being put at risk by Brazil, says Tite|
|Juventus complete signing of free agent Emre Can|
|Fred completes Manchester United switch|
|Dembele will not join a Spurs rival|
|What were the 0.4 per cent doing? Iceland captain marvels at TV audience|
|Forsberg ready for ´next big step´ after RB Leipzig|
|´Retired´ Brits on bench as Springboks ring changes for final Test|
|Meninga: Key Kangaroos positions up for grabs in Origin|
|FIFA gets shirty over Ronaldo claims|
|Soyuncu keen on Arsenal switch|
|Atmosphere much better after criticism, says Hummels|
|FIFA issues statement after ´questionable´ Amrabat decision|
|Cipriani and Robshaw to start for England at Newlands|
|Team Sky hit back at Hinault´s ´irresponsible´ Froome comments|
|Iran fans are the real winners as women get glimpse of the future|
|Beckham predicts England-Argentina World Cup final|
|Napoli should sign Meret, Zenga claims|
|Meticulous Mouratoglou shaping stars of the future|
|Journalist hands Khedira boarding pass for early flight home|
|Germany v Sweden: Muller upbeat ahead of huge World Cup clash|
|South Korea v Mexico: Germany´s conquerors set for role reversal|
|Chandimal appeals against one-match ban|
|Fofana and Lamerat start, Parra skipper for final All Blacks Test|
|Asia and Africa being left behind - Queiroz|
|Emre Can arrives for Juventus medical|
|Championship fixtures: Bielsa´s Leeds face Stoke while Lampard´s Derby go to Reading|