(Reuters) - Highlights of the second day at the U.S. Open, the final Grand Slam tournament of the year, on Tuesday (times GMT):
0251 SABALENKA QUELLS AZARENKA CHALLENGE
Aryna Sabalenka defeated former world number one Victoria Azarenka 3-6 6-3 6-4 in the first competitive of the Belarusians.
Earlier, three-times champion Rafa Nadal powered past Australia's John Millman 6-3 6-2 6-2 to set up a second round meeting with wildcard Thanasi Kokkinakis.
Nadal sends Millman to U.S. Open exit
Gauff delivers on the hype in thriller
Canadian Pospisil stuns Khachanov
Fabulous Fabbiano stuns Thiem in first round
Halep ends string of first-round losses
Holder Osaka survives Blinkova test
Riske battles back to oust Muguruza
Rublev sends Tsitsipas packing at U.S. Open
Tsitsipas lashes out at umpire during loss
Canada's Andreescu eases into second round
Bautista Augut upset by Kukushkin
U.S. Open order of play on Wednesday
Serena, Djokovic headline Day Three action
2350 KHACHANOV CRASHES OUT AFTER DEFEAT BY POSPISIL
Ninth seed Karen Khachanov of Russia crashed out in the first round after losing 4-6 7-5 7-5 4-6 6-3 to Canada's Vasek Pospisil.
Khachanov was the fourth top 10 seed to exit the men's draw on Tuesday, following in the footsteps of Roberto Bautista Agut (10), Dominic Thiem (4), and Stefanos Tsitsipas (8).
2340 GAUFF COMES FROM BEHIND TO BEAT POTAPOVA
Cori "Coco" Gauff bounced back from a set down to beat Russia's Anastasia Potapova 3-6 6-2 6-4 and reach the second round on her U.S. Open debut.
The 15-year-old American made 11 double faults, but balanced that out by winning 73% of her first serves, and shaded the contest despite making one more unforced error and hitting two fewer winners than her higher-ranked opponent.
2300 SANDGREN SEES OFF TSONGA CHALLENGE
American Tennys Sandgren recovered well from a disappointing start to beat Jo-Wilfried Tsonga 1-6 6-7(2) 6-4 7-6(5) 7-5, helped by the Frenchman making 58 unforced errors during the first round match.
2250 CHUNG SCRAPES PAST ESCOBEDO
South Korea's Chung Hyeon fought past Ernesto Escobedo 3-6 6-4 6-7(5) 6-4 6-2 in his opening match at Flushing Meadows.
Chung showed a deft touch at the net, where he won 21 of 25 points, and also sent down 64 winners to reach the second round for the fourth time in his career.
2210 WOZNIACKI BOUNCES BACK AGAINST WANG
Caroline Wozniacki overcame a slow start to beat China's Wang Yafan 1-6 7-5 6-3. The 19th seed lost the first five games before getting on the board to avoid being bagelled. She edged a tight second set but settled into her stride in the third.
2154 ZVEREV SURVIVES ALBOT ONSLAUGHT
Sixth seed Alexander Zverev was given a mid-match fright by Moldova's Radu Albot but rediscovered his touch in the final set to advance 6-1 6-3 3-6 4-6 6-2.
The majority of the German's 57 unforced errors came in the third and fourth sets, but he still managed to send down nine aces and fire 49 winners to get past Albot, the world number 41.
2137 FABBIANO STUNS FOURTH SEED THIEM
Unfancied Thomas Fabbiano of Italy stunned fourth seed Dominic Thiem 6-4 3-6 6-3 6-2 to advance to the second round.
The world number 87, who upset Stefanos Tsitsipas in the first round at Wimbledon this year, converted four of eight break points and made only 20 unforced errors compared with 48 by Thiem to send the Austrian home early.
2130 ANDUJAR OUTLASTS EDMUND IN MARATHON MATCH
Spain's Pablo Andujar beat Britain's Kyle Edmund 3-6 7-6(1) 7-5 5-7 6-2 in a gruelling clash lasting four hours, 21 minutes.
Edmund paid the price for making 77 unforced errors, although he served 12 aces to Andujar's seven.
2120 HALEP GETS PAST GIBBS IN THREE SETS
Wimbledon champion Simona Halep produced a typically tenacious performance to beat 135th-ranked American Nicole Gibbs 6-3 3-6 6-2.
The Romanian fourth seed looked far from her best, making 42 unforced errors, but struck 34 winners en route to closing out the first-round contest in one hour, 51 minutes.
2045 COLLINS SQUEEZES PAST HERCOG
American Danielle Collins won a tight three-setter against Polona Hercog of Slovenia, prevailing 6-3 4-6 6-4 to progress to round two. Collins hit 28 winners to her opponent's 23 and made two fewer unforced errors.
2030 KONTAVEIT CRUSHES SORRIBES TORMO
Estonian Anett Kontaveit cruised into round two after demolishing world number 83 Sara Sorribes Tormo 6-1 6-1.
The 21st seed won 13 of 16 points at the net and struck 25 winners compared with four from her opponent, who also struggled to convert her first serves into points.
1950 ISNER EASES PAST GARCIA-LOPEZ
Big-serving American John Isner beat Spain's Guillermo Garcia-Lopez 6-3 6-4 6-4. The 14th seed sent down 29 aces, hit 55 winners, won 20 of 26 points at the net and saved the only break point he faced to ease into the second round.
1918 TSITSIPAS STUNNED BY RUBLEV
Eighth seed Stefanos Tsitsipas of Greece lost 6-4 6-7(5) 7-6(7) 7-5 to unseeded Russian Andrey Rublev in the first round.
He made 81 unforced errors and struggled on serve throughout the nearly four-hour contest at Louis Armstrong Stadium.
1848 OSAKA BATTLES PAST BLINKOVA
Top seed and defending champion Naomi Osaka of Japan was pushed to three sets by world number 84 Anna Blinkova, and had to battle hard to beat the unseeded Russian 6-4 6-7(5) 6-2 and reach the second round.
Osaka hit eight aces and 44 winners but also made 50 unforced errors during the match.
1845 KUKUSHKIN OUSTS 10TH SEED BAUTISTA AGUT
Unseeded Mikhail Kukushkin of Kazakhstan served up an early upset by beating 10th seed Roberto Bautista Agut of Spain 3-6 6-1 6-4 3-6 6-3 in an epic encounter lasting more than three hours.
1835 BERTENS STORMS PAST BADOSA
Seventh seed Kiki Bertens made quick work of Paula Badosa, beating the Spaniard 6-4 6-2 to advance to the second round. Bertens hit 23 winners and won nine more points at the net as she wrapped up the contest in just over an hour.
1801 BERRETTINI CLAIMS FIRST WIN IN MAIN DRAW
Italy's Matteo Berrettini beat Frenchman Richard Gasquet 6-4 6-3 2-6 6-2 to advance to the U.S. Open second round for the first time in his career.
The 23-year-old fired 18 aces in beating his veteran opponent in two hours and 43 minutes.
1730 MUGURUZA DUMPED OUT IN FIRST ROUND BY RISKE
American Alison Riske came back from a set down to beat 24th seed Garbine Muguruza 2-6 6-1 6-3 in a match that lasted just over two hours. Riske converted seven break points and smashed 39 winners to advance.
1700 BENCIC SAILS INTO SECOND ROUND
Swiss Belinda Bencic marched into the second round with a comfortable 6-3 6-2 victory over Luxembourg's Mandy Minella, wrapping up the match in 67 minutes.
1635 KVITOVA THROUGH IN STRAIGHT SETS
Petra Kvitova eased past Czech compatriot Denisa Allertova with a 6-2 6-4 victory to move into the second round.
Kvitova, who was runner-up at the Australian Open this year, converted four break points and smashed 16 winners while Allertova double faulted six times and made 33 unforced errors to hand the sixth seed the win in 79 minutes.
1520 PLAY UNDER WAY IN NEW YORK
Play began in bright sunshine with the temperature hovering around 21 degrees Celsius (69.8°F) and a forecast high of 23C.
(Compiled by Rohith Nair, Simon Jennings and Shrivathsa Sridhar in Bengaluru; Editing by Toby Davis and Emelia Sithole-Matarise)