New York - Former champion Juan Del Potro was made to work on a wet Wednesday, with the sixth seed squeezing into the second round of the US Open after fighting off a challenge from Spain's Guillermo Garcia-Lopez.
The sixth-seeded Argentine came through on his fourth match point for a 6-3, 6-7 (5-7), 6-4, 7-6 (9-7) win in four-and-three-quarter hours on a day badly delayed by rain.
The match was halted for two-and-a-quarter hours in the opening afternoon stages while drizzly weather passed.
The night-time finish sends 2009 winner Del Potro into the next round against German Peter Gojowczyk, who beat Igor Sijsling 7-6 (9-7), 2-6, 6-4, 6-1. The winner hit 13 aces and 52 winners in his victory.
In other results, Marcos Baghdatis beat Go Soeda 6-4, 6-3, 6-1, South African Kevin Anderson stopped German Daniel Brands 7-5, 4-6, 6-2, 6-3 and Russian Mikhail Youzhny put out France's Nicolas Mahut 6-4, 6-4, 7-6 (7-4).
Women's seeds Agnieszka Radwanska and Li Na got in quick second-round wins early in the day before rain and the threat of lightning arrived in the afternoon in the first of the weather delays.
The conditions forced officials to cancel matches, including four featuring women's seeds: number one Serena Williams, eighth seed Angelique Kerber, number nine Jelena Jankovic and 16th-seeded Sabine Lisicki.
Number three Radwanska beat Spain's Maria Torro-Flor 6-0, 7-5 while former French Open winner Li, seeded fifth, defeated Swede Sofia Arvidsson 6-2, 6-2.
China's Li needed a mere 64 minutes to earn her win in three days to reach the third round at an event whose bizarre scheduling could well see men's third seed Andy Murray not even starting before Thursday if poor weather continues as forecast for the rest of the day.
Li struck 29 winners to just four for her opponent and was relieved to get off court quickly.
"I was a little bit happy, because at least I'm done for my job today," she said, adding that she felt lucky to finish before the rain came.
"I didn't have to wait and warm up and come to the court again."
Radwanska got through in just under 90 minutes, helped by 10 double-faults from her 103rd-ranked Spanish opponent who only began her grand slam career this season.
" played the first match and then I'm done. I can just relax. Sometimes it's good to play first even when I have to wake up really early, especially, you know, it's always traffic so we have to really leave early from the hotel."
Briton Laura Robson played with painkillers for a healing wrist injury to beat Caroline Garcia 6-4, 7-6 (7-5) while grand slam semi-finalist Zheng Jie of China beat former champion Venus Williams 6-3, 2-6, 7-6 (7-5).
"I definitely wish that I was playing the third round, but it's not to be for me this year," said the 33-year-old. "I tried, really, she played well. She just went for every shot. Unfortunately I didn't play consistently enough."
US Open results on Wednesday (x denotes seeded player):
Alex Bogomolov (RUS) bt Benoit Paire (FRA x24) 7-5, 2-6, 6-4, 5-7, 7-6 (7/5)
Tim Smyczek (USA) bt James Duckworth (AUS) 3-6, 6-2, 6-4, 6-1
Marcel Granollers (ESP) bt Jurgen Zopp (EST) 6-1, 3-6, 1-6, 6-3, 6-4
Rajeev Ram (USA) bt Fabio Fognini (ITA x16) 6-1, 6-2, 6-2
Aleksandr Dolgopolov (UKR) bt David Goffin (BEL) 6-2, 6-4, 6-4
Mikhail Youzhny (RUS x21) bt Nicolas Mahut (FRA) 6-4, 6-4, 7-6 (7/4)
Evgeny Donskoy (RUS) bt Jurgen Melzer (AUT x29) 7-5, 6-3, 7-6 (7/3)
Peter Gojowczyk (GER) bt Igor Sijsling (NED) 7-6 (9/7), 2-6, 6-4, 6-1
Lleyton Hewitt (AUS) bt Brian Baker (USA) 6-3, 4-6, 6-3, 6-4
Juan Martn Del Potro (ARG x6) bt Guillermo Garcia-Lopez (ESP) 6-3, 6-7 (5/7), 6-4, 7-6 (9/7)
Andy Murray (GBR x3) bt Michael Llodra (FRA) 6-2, 6-4, 6-3
Leonardo Mayer (ARG) bt Victor Hanescu (ROM) 7-6 (7/4), 6-4, 3-6, 7-6 (7/4)
Andreas Seppi (ITA x20) bt Xavier Malisse (BEL) 6-3, 3-6, 7-5, 7-5
Somdev Devvarman (IND) bt Luks Lacko (SVK) 4-6, 6-1, 6-2, 4-6, 6-4
Stanislas Wawrinka (SUI x9) bt Radek Stepanek (CZE) 7-6 (7/2), 6-3, 6-2
Ivo Karlovic (CRO) bt James Blake (USA) 6-7 (2/7), 3-6, 6-4, 7-6 (7/2), 7-6 (7/2)
Marcos Baghdatis (CYP) bt Go Soeda (JPN) 6-4, 6-3, 6-1
Kevin Anderson (RSA x17) bt Daniel Brands (GER) 7-5, 4-6, 6-2, 6-3
Jamie Hampton (USA x23) bt Kristina Mladenovic (FRA) 7-5, 6-4
Sloane Stephens (USA x15) bt Urszula Radwanska (POL) 6-1, 6-1
Zheng Jie (CHN) bt Venus Williams (USA) 6-3, 2-6, 7-6 (7/5)
Carla Suarez Navarro (ESP x18) bt Coco Vandeweghe (USA) 6-3, 6-4
Agnieszka Radwanska (POL x3) bt Maria-Teresa Torro-Flor (ESP) 6-0, 7-5
Anastasia Pavlyuchenkova (RUS x32) bt Ashleigh Barty (AUS) 6-4, 6-0
Laura Robson (GBR x30) bt Caroline Garcia (FRA) 6-4, 7-6 (7/5)
Li Na (CHN x5) bt Sofia Arvidsson (SWE) 6-2, 6-2