Seventh seed Taylor Fritz was stunned by fellow American Nishesh Basavareddy in the first round of the French Open on Sunday.
Eighth seed Machac, who won gold in mixed doubles at the Paris Olympics, became the third player from his country to win an ATP 500 title, following Tomas Berdych and Radek Stepanek.
World No 1 Novak Djokovic was beaten by Tomas Machac in the Geneva Open semi-finals.
Lorenzo Musetti brushed aside Taylor Fritz in straight sets to reach his first Australian Open quarter-final, setting up a blockbuster last-eight clash with Novak Djokovic at Melbourne Park.
IMAGES from the Australian Open matches played at Melbourne Park in Melbourne on Thursday.
The day session attendance of 51,048 was some 10,000 short of day six on Friday and even less than last year's corresponding session.
Spain bounced back from an opening singles defeat on Thursday to beat the Czech Republic 2-1 and reach the Davis Cup semi-finals for the first time in six years where they will face Germany, who earned their own comeback win over Argentina.
Novak Djokovic became the oldest man to reach the quarter-finals at all four Grand Slams in a single season.
Sumit Nagal was beaten in straight sets by World No 25 Tomas Machac in the first round of the men's singles on Sunday.
Renata Zarazua, the only Mexican player in the US Open main draw, pulled off a stunning upset by beating sixth seed Madison Keys in the first round.
Novak Djokovic is bidding to become only the third man in history to win 100 ATP titles.
Tenth seed Lorenzo Musetti rallied from a set down to beat Frenchman Giovanni Mpetshi Perricard in the first round of the US Open on Tuesday even as Carlos Alcaraz mauled big-serving American Reilly Opelka and veteran Venus Williams made an emotional exit.
Jannik Sinner's bid to win back-to-back Halle Open titles was ended on Thursday
Sumit Nagal will take on Tomas Machac of the Czech Republic in the opening round of the Australian Open
Canada are close to securing a place in the Davis Cup final Eight after a commanding 3-0 victory over Finland while Australia cruised to a 3-0 victory over the Czech Republic
Czech duo Siniakova and Machac win mixed doubles gold
Jannik Sinner secured the year-end world number one ranking by beating Czech 30th seed Tomas Machac in the Shanghai Masters semi-finals.
Carlos Alcaraz defeated Tallon Griekspoor of the Netherlands 6-1, 6-2 at the China Open on Sunday to capture his 200th career tour victory.
Top seed Carlos Alcaraz of Spain and No. 8 seed Hubert Hurkacz of Poland will clash in the ABN Amro Open semi-finals on Saturday after both posted victories on Friday in Rotterdam, Netherlands.
Rohan Bopanna and Nicolas Barrientos bowed out of the Australian Open men's doubles with an opening-round loss to the Spanish team of Pedro Martinez and Jaume Munar.
Carlos Alcaraz secured his passage into the fourth round of the Australian Open with a 6-2, 6-4, 6-7(3), 6-3 victory over Nuno Borges.
Images from the US Open men's singles second round matches, at Flushing Meadows, New York, on Thursday.
Italy's Matteo Berrettini beat Brazil's Joao Fonseca to give his side a flying start and Matteo Arnaldi then outlasted Thiago Monteiro to put the hosts into a 2-0 lead.
Flattens Faria in 2nd round to advance in Melbourne
A solitary break in the eighth game was all Djokovic needed to take the opening set, as the 37-year-old looked in total control despite playing well within himself in perfect conditions at a packed centre court.
Images from the men's singles Round of 16 matches at the US Open on Monday.
A summary of the day's tennis action at Roland Garros.
Images from Day 7 of the 2024 French Open.
Novak Djokovic dug out a 6-7(4) 6-1 6-4 win over Czech Jakub Mensik on Friday to advance to the semi-finals of the Shanghai Masters, where he will face Taylor Fritz.
All the action from Day 4 at the Australian Open on Wednesday
Briton Andy Murray will make his comeback from injury at this month's Geneva Open after the former world number one was handed a wildcard by the organisers of the French Open tune-up event on Wednesday.
Rohan Bopanna, the seasoned Indian tennis maestro, etched his name in history by securing a spot in his inaugural Australian Open men's doubles final.
Andy Murray will not get another chance to feature on court in his farewell at the Grand Slam.
World number one Jannik Sinner's bid for a second Grand Slam title continued to gain momentum as he thumped Christopher O'Connell 6-1, 6-4, 6-2 on Saturday to reach the US Open fourth round.
Zheng Qinwen saw off a spirited challenge from Diana Shnaider to secure a hard-fought 7-6(5), 6-3 win in their Pan Pacific Open semi-final on Saturday and set up a title clash against American Sofia Kenin.
Murray, who in 2013 ended a 77-year wait for a British men's singles champion at Wimbledon and won the title again in 2016, had previously said he was unlikely to continue his career beyond this year and could bow out at the Olympics in Paris.
Carlos Alcaraz will be backed to extend his winning run at the Grand Slams to 16 matches following triumphant French Open and Wimbledon campaigns.
Spain's dream team met its match as Rafael Nadal and Carlos Alcaraz's hopes of an Olympic doubles gold medal were ended by American duo Rajeev Ram and Austin Krajicek on Wednesday.
Zheng Qinwen became the first Chinese player to win an Olympic tennis singles gold medal when she held off Croatia's Donna Vekic for a 6-2, 6-3 win in a tense final on Saturday.
The Spaniard needed less than 90 minutes to dispatch the 23rd seed from Italy