New York - Roger Federer claimed his 50th win of 2014 on Tuesday as the 17-time major winner got his campaign for a record sixth US Open off to a battling start.
The great Swiss, playing in his 60th successive Grand Slam event and bidding to become the oldest major winner in over 40 years, defeated Australia's Marinko Matosevic 6-3, 6-4, 7-6 (7/4) to register his 23rd win in 24 night matches in New York.
"It was a bit more difficult than I thought it was going to be in the third set," said Federer who had been cruising with a break in the third before Matosevic briefly rallied.
Federer next faces another Australian, big-serving Sam Groth for a place in the last 32.
"Marinko has got a big game. He serves and volleys so it gave me a chance to hit some good passing shots."
Second seeded Federer, who hit 10 aces and 41 winners and was cheered on by basketball legend Michael Jordan, found himself sharing the headlines on the second day at Flushing Meadows with teenage upstarts CiCi Bellis and Borna Coric.
Bellis, ranked at a lowly 1,208 and aged just 15, caused the biggest upset when she knocked out Australian Open runner-up, Dominika Cibulkova, the 12th seed, 6-1, 4-6, 6-4 to become the youngest player to win a match at the US Open since Anna Kournikova in 1996.
"I went into the match thinking it was going to be such a great experience, but I never thought I would come out on top winning," said Bellis who, as an amateur, had to pass up the $60,000 prize money to avoid jeopardising a college sports career.
Coric, the 17-year-old world number 204 who was junior champion in 2013, also made a stunning Grand Slam debut with a convincing 6-4, 6-1, 6-2 win over 29th-seeded Czech Lukas Rosol, the man who dumped Rafael Nadal out of Wimbledon two years ago.
The upset put Coric into a second-round clash with history-making Victor Estrella Burgos, the Dominican Republic's first Grand Slam participant who is making his US Open debut at 34.
"It's an amazing feeling," said qualifier Coric, who arrived in New York with the goal of making it into the main draw. "I said to myself, 'If I achieve that, that's going to be perfect'."- Williams closes programme -
Wimbledon champion Petra Kvitova breezed into the second round with a 6-1, 6-0 rout of French number 73 Kristina Mladenovic.
The third-seeded Czech didn't surrender a service break in the 54-minute contest, breaking Mladenovic five times.
Canadian seventh seed Eugenie Bouchard, the Wimbledon runner-up, eased past Olga Govortsova of Belarus 6-2, 6-1, slamming the brakes on her post-All England Club final slump which had brought her just one win coming into New York.
Bouchard is one of four Canadians in the main draw this year, the most since 1989 and is aiming to keep up her record of having made at least the semi-finals at all the majors in 2014.
Former French Open champion Ana Ivanovic, the eighth seed, eased past Alison Riske of the United States, 6-3, 6-0 in a tie which featured eight breaks of serve.
World number one Serena Williams, the double defending champion who is seeking a sixth title, completes the Tuesday programme against 18-year-old compatriot Taylor Townsend.
Williams, an 17-time major winner, has failed to make it past the fourth round at the Australian Open, French Open and Wimbledon this year.
Australia's Samantha Stosur, the 2011 champion, went through with a 6-1, 6-4 win over Lauren Davies of the United States, firmly erasing the nightmare of her 2013 first round exit to US teenager Victoria Duval.
However, another former champion, Svetlana Kuznetsova, the 2004 winner was dumped out 3-6, 6-2, 7-6 (7/3) by New Zealand's Marina Erakovic who won her first US Open match at the fifth time of asking.
Victoria Azarenka, the runner-up to Williams for the last two years, defeated Japan's Misaki Doi 6-7 (3/7), 6-4, 6-1 as the 16th seed looks to resurrect a season wrecked by a left foot injury which restricted her to one event in six months in the first half of 2014.
Two-time men's semi-finalist David Ferrer, the Spanish fourth seed, was also a Tuesday winner, beating Bosnia's Damir Dzumhur 6-1, 6-2, 2-6, 6-2.
America's top hope, 13th seeded John Isner saw off compatriot Marcos Giron 7-6 (7/5), 6-2, 7-6 (7/2) as he bids to end the United States' 11-year wait for a men's Grand Slam title.Results on Tuesday from the second day of the US Open, the final Grand Slam tournament of 2014 (x denotes seeded player):
Sam Querrey (USA) bt Maximo Gonzalez (ARG) 6-2, 4-6, 6-4, 4-6, 6-3
Guillermo Garcia-Lopez (ESP x28) bt Lu Yen-Hsun (TPE) 6-4, 6-2, 6-2
Jan-Lennard Struff (GER) bt Mikhail Kukushkin (KAZ) 2-6, 3-6, 6-3, 6-3, 7-5
John Isner (USA x13) bt Marcos Giron (USA) 7-6 (7/5), 6-2, 7-6 (7/2)
Kei Nishikori (JPN x10) bt Wayne Odesnik (USA) 6-2, 6-4, 6-2
Pablo Andujar (ESP) bt Jack Sock (USA) 6-4, 3-6, 6-1 - retired
Borna Coric (CRO) bt Lukas Rosol (CZE x29) 6-4, 6-1, 6-2
Victor Estrella Burgos (DOM) bt Igor Sijsling (NED) 2-6, 6-4, 6-3, 6-2
Gilles Simon (FRA x26) bt Radu Albot (MDA) 6-3, 6-4, 6-2
Federico Del Bonis (ARG) bt Noah Rubin (USA) 6-4, 6-3, 6-0
Bernard Tomic (AUS) bt Dustin Brown (GER) 7-6 (7/2), 6-4, 7-6 (7/3)
David Ferrer (ESP x4) bt Damir Dzumhur (BIH) 6-1, 6-2, 2-6, 6-2
Gael Monfils (FRA x20) bt Jared Donaldson (USA) 6-4, 6-2, 6-4
Alejandro Gonzalez (COL) bt Dmitry Tursunov (RUS) 6-4, 6-4, 7-5
Paolo Lorenzi (ITA) bt Yoshihito Nishioka (JPN) 6-1, 6-2, 2-1 - retired
Richard Gasquet (FRA x12) bt Denis Istomin (UZB) 7-5, 7-6 (7/5), 6-4
Fabio Fognini (ITA x15) bt Andrey Golubev (KAZ) 6-4, 6-4, 6-2
Adrian Mannarino (FRA) bt Pere Riba (ESP) 3-6, 7-5, 6-3, 6-2
Tim Smyczek (USA) bt Filip Krajinovic (SRB) 4-6, 6-3, 6-2, 7-6 (7/5)
Roberto Bautista (ESP x17) bt Andreas Haider-Maurer (AUT) 5-7, 7-6 (7/1), 1-6, 7-5, 6-1
Ivo Karlovic (CRO x25) bt Jarkko Nieminen (FIN) 6-4, 6-4, 3-6, 6-4
Marcel Granollers (ESP) bt Jurgen Melzer (AUT) 7-6 (7/1), 6-3, 6-2
Sam Groth (AUS) bt Albert Ramos (ESP) 6-3, 7-6 (7/5), 6-3
Roger Federer (SUI x2) bt Marinko Matosevic (AUS) 6-3, 6-4, 7-6 (7/4)
Serena Williams (USA x1) bt Taylor Townsend (USA) 6-3, 6-1
Vania King (USA) bt Francesca Schiavone (ITA) 6-3, 3-6, 6-3
Varvara Lepchenko (USA) bt Alison Van Uytvanck (BEL) 7-5, 6-2
Mona Barthel (GER) bt Zhang Shuai (CHN x32) 6-1, 6-2
Samantha Stosur (AUS x24) bt Lauren Davis (USA) 6-1, 6-4
Kaia Kanepi (EST) bt Pauline Parmentier (FRA) 7-6 (7/3), 3-6, 6-1
Coco Vandeweghe (USA) bt Donna Vekic (CRO) 2-6, 6-3, 6-1
Carla Suarez Navarro (ESP x15) bt Ajla Tomljanovic (AUS) 3-6, 6-2, 6-1
Flavia Pennetta (ITA x11) bt Julia Goerges (GER) 6-3, 4-6, 6-1
Shelby Rogers (USA) bt Maryna Zanevska (UKR) 6-4, 6-3
Nicole Gibbs (USA) bt Caroline Garcia (FRA) 6-2, 2-6, 6-3
Anastasia Pavlyuchenkova (RUS x23) bt Teliana Pereira (BRA) 6-2, 6-0
Casey Dellacqua (AUS x29) bt Patricia Mayr-Achleitner (AUT) 7-5, 6-3
Wang Qiang (CHN) bt Paula Kania (POL) 6-2, 6-0
Karolina Pliskova (CZE) bt Yvonne Meusburger (AUT) 6-2, 6-2
Ana Ivanovic (SRB x8) bt Alison Riske (USA) 6-3, 6-0
Petra Kvitova (CZE) bt Kristina Mladenovic (FRA) 6-1, 6-0
Petra Cetkovska (CZE) bt Klara Koukalova (CZE) 6-1, 2-6, 6-3
Aleksandra Krunic (SRB) bt Katarzyna Piter (POL) 6-4, 6-1
Madison Keys (USA x27) bt Jarmila Gajdosova (AUS) 6-0, 6-3
Marina Erakovic (NZL) bt Svetlana Kuznetsova (RUS x20) 3-6, 6-2, 7-6 (7/3)
Elena Vesnina (RUS) bt Chan Yung-Jan (TPE) 6-0, 7-5
Christina McHale (USA) bt Chanelle Scheepers (RSA) 6-2, 1-6, 7-6 (7/5)
Victoria Azarenka (BLR x16) bt Misaki Doi (JPN) 6-7 (3/7), 6-4, 6-1
CiCi Bellis (USA) bt Dominika Cibulkova (SVK x12) 6-1, 4-6, 6-4
Zarina Diyas (KAZ) bt Lesya Tsurenko (UKR) 6-1, 6-2
Polona Hercog (SLO) bt Elina Svitolina (UKR) 6-2, 7-6 (7/4)
Ekaterina Makarova (RUS x17) bt Grace Min (USA) 6-4, 6-2
Barbora Zahlavova Strycova (CZE x30) bt Ashleigh Barty (AUS) 6-1, 6-3
Monica Niculescu (ROM) bt Yaroslava Shvedova (KAZ) 6-7 (5/7), 6-1, 7-5
Sorana Cirstea (ROM) bt Heather Watson (GBR) 6-1, 6-1
Eugenie Bouchard (CAN x7) bt Olga Govortsova (BLR) 6-2, 6-1