Both the top seeds of the men's and women's singles, Novak Djokovic and Serena Williams, will be in action at Arthur Ashe Stadium in New York on Sunday for their respective round of 16 clashes.

Novak Djokovic has been in ominous form in the 2015 US Open as the Serb has not dropped a single set in the competition. Djokovic faces 23rd seed Bautista Agut for a place in the quarter finals of the US Open.

Djokovic, who is one of the favourites to win the title, cannot afford to take the Spaniard lightly at any cost, for Agut is a strong player, though the 23rd seed might consider himself lucky to face Djokovic.

Agut's third round opponent, 14th seed David Goffin was leading 2-1 sets, before the Belgian was forced to retire in the fourth round. On the other hand, Djokovic came up with some terrific display in his third round tie against Italian Andreas Seppi, who lost the game 3-6, 7-5 and 7-5.

The Serbian was happy with his performance, but feels he can still do better.

"Satisfied, but you can always do better. We're all perfectionists in a way. We see certain things we could have done better. But, again, a win is a win. I can't underestimate the quality of my opponent today. He is 20, 25 in the world for a reason. He's not afraid to go out on a big stadium and play his best against big players. He won against Federer earlier this year in Australia. He's a good player and it's a good win," said Djokovic.

Djokovic, who has won two out of the three grand slams this season, is on course for his third title this year, but the world number one is expected to find some stiff competition in the second week, where he could run into some top players of the circuit.

Talking about top players, Serena Williams has been the best women's player in the US Open amongst the current crop of players in the competition. The US woman had won the title six times and is gunning for an extraordinary seventh title.

Though Serena might have been troubled by fellow country woman Bethanie Lynn Mattek-Sands in the third round, the top seed played some brilliant tennis to come back after losing the first set. The final score read 3-6, 7-5 and 6-0. It is such character, which has helped her win all three grand slams of the season so far.

Serena, who heads into the match as favourite on most occasions, was happy when the crowd supported her during the clash. "I usually don't have a cheering crowd for me, so it definitely feels good. They usually cheer for the underdog, but I think everyone wants to see me go far, I guess, this year. So it's really cool to have the crowd not cheering for the underdog this time. But I understand obviously. It just feels really good. It feels amazing every time I play. I think, if anything, it helps me," said Serena.

Serena Williams will face another American, 19th seed Madison Keys in the round of 16, which is going to be an interesting affair. The 19th seed has been in an imperious form this US Open as apart from not dropping a single set, she has defeated her opponents with ease, which includes her third round victory against Poland's Agnieszka Radwańska.

Serena and Keys have only met once in their career – Australian Open 2015 semi finals – where the top seed defeated Keys in straight sets, 7-5 and 6-2.

Will a similar result take shape in 2015 US Open as well? Only time will tell.

If Serena defeats Keys and her sister, Venus emerges triumphant over Anett Kontaveit in the pre quarters, one will witness a Williams sister quarter final.

Where to Watch Live

Serena Williams vs Madison Keys is scheduled for approximately 3:30pm local time(1am IST, 8:30pm BST)start, while Novak Djokovic vs Bautista Agut match is scheduled for 7pm local time (4:30am IST, 12amBST)

Live coverage of the Serena Williams vs Madison Keys & Novak Djokovic vs Bautista Agut match will be shown live on Ten Sports in India, while the match can also be watched via live streaming online on Ten Sports Live.

Audience in Australia can watch Serena Williams vs Madison Keys & Novak Djokovic vs Bautista Agut on Fox Sports with live streaming option on Foxtel Play.

Viewers in the US can watch the US Open 2015 round of 16 Serena Williams vs Madison Keys & Novak Djokovic vs Bautista Agut match on ESPN; live stream option on Watch ESPN.

UK viewers can view the entire Day 7 action on Sky Sports, with live streaming option on Sky Sports Sky Go.