After demolishing their first-round opponents, defending Wimbledon champion Novak Djokovic and six-times winner Roger Federer return on Wednesday to face players from the opposite end of the tennis spectrum.
John Isner limped out of the Sydney International on Wednesday with his Australian Open participation in doubt but the thing that frustrated him most about his last 16 defeat was the umpire checking how long he was taking to serve.
Top seed James Blake eased into the US Clay Court Championships second round but fellow American Sam Querrey made an early exit.
15-year-old American Ryan Harrison beat Uruguayan Pablo Cuevas 6-4, 6-3 at the US Men's Clay Court Championship.
Novak Djokovic was given a scare in his North American hardcourt season opener but managed to prevail with a 7-5, 7-6(3) victory over Luxembourg's Gilles Mueller on Wednesday to reach the third round of the Rogers Cup.
Defending champion and world number one Andy Murray was swept aside by home favourite Fabio Fognini at the Italian Open on Tuesday, being completely outplayed in a 6-2, 6-4 defeat.
American Bethanie Mattek-Sands and the Czech Republic's Lucie Safarova claimed their third consecutive grand slam doubles title with a convincing 6-2, 6-1 victory over Australian duo Ashleigh Barty and Casey Dellacqua at the French Open on Sunday.
Hewitt, the 2001 champion, received his wildcard via a reciprocal agreement with Tennis Australia, which will grant an American a wild card into next year's Australian Open, and was among 16 players who received wildcard entries.
Italy's Matteo Berrettini overcame second seed Roberto Bautista Agut 7-6(9), 6-4 to win his first title at the Swiss Open in Gstaad on Sunday.
Naomi Osaka continued her stunning run of form with a 6-3, 6-2 victory over 23-times Grand Slam champion Serena Williams in the first round of the Miami Open on Wednesday, the latest big win for the 20-year-old Japanese player.
Czech defending champion Katerina Siniakova fended off Maria Sharapova in a fiercely contested match at the Shenzhen Open on Friday to set up a final with world number one Simona Halep.
A summary of sports events and persons who made news on Thursday
A summary of the action on Day 3 at the US Open.
A summary of sports events and sports persons, who made news on Sunday
Images from the Australian Open matches played at Melbourne Park on Wednesday.
PHOTOS from day four of the Wimbledon championships at the All England Lawn Tennis and Croquet Club in London on Thursday.
Former world number one Andy Murray withdrew from the Brisbane International with a hip problem on Tuesday, further putting in doubt the Briton's prospects of being fit in time for the Australian Open later this month.