Images from Day 6 of the Australian Open in Melbourne on Saturday.
Top seed Novak Djokovic regained his composure after a third-set meltdown to stave off the challenge of Canadian teenager Denis Shapovalov and reach the fourth round of the Australian Open with a 6-3, 6-4, 4-6, 6-0 victory on Saturday.
The 14-time Grand Slam winner stamped his authority early on by breaking the 19-year-old's serve three times and converted his only breakpoint opportunity in the second set while leading 5-4 to take a 2-0 lead.
The 31-year-old lost his cool in the third set, however, after his request to turn off the artificial lights was ignored and he muttered to himself angrily and before losing two consecutive break of serves to concede the set.
The Serb let out his frustration with a huge roar when he broke Shapovalov early in the fourth, though, and romped through the rest of the set to remain on course for an unprecedented seventh title at Melbourne Park.
The reigning Wimbledon and US Open champion will next meet Russian 15th seed Daniil Medvedev, who notched up his best Grand Slam showing till date by reaching the fourth round with a 6-2 7-6(3) 6-3 win over David Goffin of Belgium earlier in the day.
Halep sends Venus packing
Top seed Simona Halep had the odds stacked against her ahead of the Australian Open but the Romanian proved her title credentials with a breezy 6-2, 6-3 third round win over multiple Grand Slam winner Venus Willliams on Saturday.
The reward for the 27-year-old French Open champion is probably the toughest challenge in the women's draw at Melbourne Park, a fourth round date with the younger Williams sister, Serena.
Coming to the year's first Grand Slam on a five-match losing streak and without a coach, Halep had to grind her way through the first two rounds with tough three-set wins.
She started positively against Venus, though, and broke her twice to take the first set.
Venus showed more fight in the second and there was an early trade of breaks before Halep broke again to go 4-3 up before converting her first matchpoint with a forehand winner down the line.
Zverev cruises past Bolt
Germany's Alexander Zverev brandished his credentials as an Australian Open title contender by dispatching local wildcard Alex Bolt 6-3, 6-3, 6-2 in the third round on Saturday.
The fourth seed was tested early on his serve, which was initially off-target, but was able to maintain control of the contest with a strong returning display.
"There's always things to improve, but I think I played a good match today," said Zverev, who will play big-serving Canadian Milos Raonic in the fourth round.
After losing his serve once in the first set -- and breaking three times -- Zverev filled in any holes that could be exploited and picked up his first serve percentage to ease the pressure.
He started to hold serve more comfortably and deftly handled the left-handed sliding serves delivered from the other end.
Bolt's forehand constantly switched between being an asset and a liability, with the stylish left-handed swing prone to both screaming winners and over-hitting that opened up break opportunities the German gladly accepted.
"It's sort of a blessing and a curse sometimes," said Bolt.
"I may have all this power, but sometimes the control isn't always there. Sometimes what I struggle with is finding that balance between going for too much and not going for enough."
Zverev promptly served out the match and muted his celebrations, aware that he had just outclassed a local favourite who had won over the crowd.
The result ended the uplifting run of the 26-year-old Australian who was digging ditches on building sites just three years ago during a career crisis of confidence.
Bolt entered the Australian Open without having previously won a match in a Grand Slam, but showed he belonged in the majors with two victories, which included a win over seasoned Frenchman Gilles Simon.
Serena motors into Round 4
Serena Williams powered into the fourth round of the Australian Open on Saturday with a 6-2, 6-1 demolition of Ukrainian teenager Dayana Yastremska to continue her charge through the Melbourne Park draw.
The 37-year-old Williams, chasing a record-extending eighth Melbourne title in the professional era, barely broke sweat on a sunny afternoon at Rod Laver Arena as she sent 20 winners flying past the 57th-ranked 18-year-old.
Yastremska rolled her right ankle midway through and took a medical time-out to have her foot bandaged when trailing 4-1 in the second set.
It stalled defeat only briefly, however, as Williams broke her a third time in the set and claimed the match when the Ukrainian sprayed a cross-court forehand wide.
Williams will play the winner of the match between her older sister Venus and top seed Simona Halep for a place in the quarter-finals.
Osaka survives scare
US Open champion Naomi Osaka survived a huge scare against Hsieh Su-wei before overhauling the Taiwanese 5-7, 6-4, 6-1 to reach the fourth round of the Australian Open on Saturday.
The Japanese fourth seed was driven to distraction by double-sided Hsieh's angled shots and stout defence, and was staring down the barrel at 4-2 in the second set at Margaret Court Arena.
Hsieh's serve crumbled, however, and Osaka claimed 10 of the last 11 games to close out the match in a barrage of power hitting.
Osaka will play the winner of Wang Qiang and Anastasija Sevastova for a place in the quarter-finals.
Nishikori eases into fourth round
Japan's Kei Nishikori moved swiftly into the fourth round of the Australian Open on Saturday after beating Joao Sousa of Portugal 7-6(6), 6-1, 6-2.
The comfortable victory will come as a relief to the eighth seed and former US Open finalist after he battled through consecutive five-set matches in the opening rounds.
After a tight first set, Nishikori took control of the match, increasing the pace on his ground strokes and showing soft hands at the net.
Nishikori will play the winner of Pablo Carreno Busta and Fabio Fognini in the fourth round.
Svitolina beats Zhang in thriller
Sixth seed Elina Svitolina rallied from 3-0 down in the final set to beat China's Zhang Shuai 4-6, 6-4, 7-5 in just under three hours on Rod Laver Arena.
The 24-year-old Ukrainian will meet Belgian Elise Mertens or American Madison Keys in the last 16.