Images from Day 8 of the Australian Open in Melbourne on Monday.
Serena Williams staved off a spectacular fight-back from World No 1 Simona Halep to win 6-1, 4-6, 6-4 and reach the quarter-finals of the Australian Open on Monday.
French Open champion Halep broke Williams's serve in the first game but that was the only one she managed for the rest of the opening set as the 23-time Grand Slam champion bulldozed her way through the set in 20 minutes, serving it out with an ace.
The victory was a major step towards the 37-year-old US great equalling Australian Margaret Court's all-time record of 24 Grand Slam wins as she powered into the last eight.
It looked as if she would breeze through the match after the opening set mauling she had handed out but the World No 1 Halep had other plans as she fought back to level the contest at one set apiece 1-1 after breaking Williams a second time.
Following an attritional first few games, the seven-times Australian Open champion got the crucial break of serve in the seventh game of the decider and sealed the match in an hour and 47 minutes when Halep hit a forehand out.
"It was a really intense match and there were some incredible points but I love playing tennis... It's really cool to be back out and playing again on this court," Williams said in her courtside interview.
"I really needed to elevate my game, she's the number one player in the world and there's a reason why.
"In order for me to stay out there, I just had to play a little bit like I knew I could, and I did."
For a place in the semi-finals, Williams will meet Czech seventh seed Karolina Pliskova, who thrashed twice Grand Slam champion Garbine Muguruza 6-3, 6-1 earlier on Monday.
Djokovic passes Medvedev test to make Melbourne last-eight
Novak Djokovic struck back for the old guard at the Australian Open soaking up the pressure from a willing Daniil Medvedev before crushing the young Russian 6-4, 6-7(5), 6-2, 6-3 to reach his 10th quarter-final at Melbourne Park.
The night after Roger Federer was stunned by Greek tyro Stefanos Tsitsipas, there was another sniff of an upset at Rod Laver Arena as 22-year-old Medvedev rocked the Serb with a furious assault of power hitting.
Yet the Russian wearied in the constant attrition, and top seed Djokovic cruised to victory, having passed easily his biggest test at the tournament.
The world number one will continue his bid for a hat-trick of Grand Slam titles and a record seventh at Melbourne Park against eighth seed Kei Nishikori.
Nishikori battles back in five-hour epic to reach quarters
An exhausted Kei Nishikori battled from two sets down to outlast Spain's Pablo Carreno Busta 6-7(8), 4-6, 7-6(4), 6-4, 7-6(8) in an epic encounter on Monday and book his place in the Australian Open quarter-finals.
Dragged into a five-set dogfight for the third time in four rounds, Nishikori struggled to deal with the physical and mental strain early on as Carreno Busta took a two-set lead but the eighth seed clawed his way back to level the contest.
The Japanese blew an early a break in the fifth set but prevailed in the tiebreaker to seal the win in five hours and five minutes, much to the delight of his compatriots in the crowd at Margaret Court Arena.
Big-serving Milos Raonic eased into the Australian Open quarter-finals with a surprisingly one-sided 6-1, 6-1, 7-6(5) victory over frustrated fourth seed Alexander Zverev, who smashed his racket to a pulp as Monday's match was slipping away.
The 21-year-old German, who won the 2018 ATP Finals but has struggled at the Grand Slams, was broken six times in the first two sets before the Canadian converted his fourth match point in a tight third set to seal the contest in less than two hours.
After serving his fifth double-fault to cough up a second break in the second set, Zverev lost his temper and hammered his racquet into the ground until it was mangled, earning him a code violation warning from the umpire.
The 28-year-old Raonic will face either Croatian 11th seed Borna Coric or Frenchman Lucas Pouille, who is seeded 28th, for a place in the semi-finals.
Pouille reels in Coric to make first Melbourne quarter-final
A slow-starting Lucas Pouille rallied from a set down to overcome Borna Coric 6-7(4), 6-4, 7-5, 7-6(2) and advance to the Australian Open quarter-finals for the first time on Monday.
The Frenchman made hard work of the fourth set, allowing 11th seed Coric to break back and drag the match into a tiebreak in the twilight at Melbourne Arena.
Pouille raised his game when it mattered, however, flicking a delightful lob over Coric to move within two points of victory.
The 28th seed Pouille grabbed four match points when Coric netted a volley and converted the first of them when the Croat hammered a shot over the baseline.
Pouille will meet 16th seed Milos Raonic for a place in the semi-finals.
Pliskova pounds Muguruza to reach quarters
Karolina Pliskova thrashed twice Grand Slam champion Garbine Muguruza 6-3, 6-1 on Monday to reach the Australian Open quarter-finals for the third time in succession.
The Czech seventh seed broke former Wimbledon champion Muguruza five times in the one-sided clash in the afternoon sunshine at Margaret Court Arena.
Needing only 24 minutes to win the second set, Pliskova earned two match points on Muguruza's serve and sealed the win when the out-of-sorts Spaniard smashed a backhand long.
Pliskova will meet the winner of top seed Simona Halep and Serena Williams for a place in the semi-finals as she continues her bid for a maiden Grand Slam.
Osaka rallies to enter quarters
US Open champion Naomi Osaka completed another comeback victory to overhaul 13th seed Anastasija Sevastova 4-6, 6-3, 6-4 and reach the quarter-finals of the Australian Open on Monday.
The Japanese fourth seed, who had to fight back from a set down against Hsieh Su-Wei in her previous match, was far from her best as she struggled to hold serve and berated herself regularly during the sun-bathed clash at Rod Laver Arena.
She held firm when it counted, however, breaking Sevastova in the seventh game of the decider before sealing the match after one hour and 47 minutes with an imperious forehand down the line.
Osaka will play sixth seed Elina Svitolina for a place in the semi-finals.
Svitolina staves off Keys challenge
Elina Svitolina booked a spot in the Australian Open quarter-finals with a 6-2, 1-6, 6-1 win over American Madison Keys on Monday.
The sixth-seeded Ukrainian, who won the 2018 WTA Finals in Singapore, breezed through the first set with two break of serve before Keys roared back in the second, taking a 5-0 lead before converting her second set point to level the match.
Svitolina, 24, saved five break points during a marathon hold of serve in the decider before breaking 2017 US Open finalist Keys twice and then converting her first match point to seal the contest in an hour and 36 minutes.
