Indian Wells - Rafael Nadal's Indian Wells title defence got off to a rocky start on Saturday, as the world number one was forced to rally for a three-set victory over Radek Stepanek.
Nadal needed nearly two and a half hours to get past the talented Czech 2-6, 6-4, 7-5, eight double faults doing little to help his cause in the second-round clash.
Wimbledon champion Andy Murray, the fifth seed, fought back from a set down against another Czech, subduing Lukas Rosol 4-6, 6-3, 6-2.
The going was easier for four-time champion Roger Federer and fellow Swiss Stanislas Wawrinka, who is playing his first tournament since his Australian Open triumph.
Federer, the former world number one who has fallen to eighth in the world and is seeded seventh here, defeated France's Paul-Henri Mathieu 6-2, 7-6 (7/5).
Wawrinka, seeded third, downed Croatian Ivo Karlovic 6-3, 7-5 in just 63 minutes.
"It was a difficult match to start against Ivo," said Wawrinka, who didn't face a break point and answered nine aces from Karlovic with eight aces of his own. "It's never easy. He's a tough player.
"He doesn't give you so much rhythm. "But I'm really happy the way I was playing, the way I was aggressive on the court, and to win in straight sets was really important for me."
Nadal said Stepanek was a similarly tough opening opponent, his unpredictability making it hard to get in a groove.
"What you want to find in the first (match) is rhythm, and against him every point is different," Nadal said.
Nadal appeared to have gained control of the contest when he won the second set with a single service break and broke again to open the third.
He immediately gave the break back, however, and had to save three break points before holding in the sixth game.
"It was a tricky situation in the 0-40," said Nadal, who responded to the danger with a service winner, an ace and a backhand passing winner.
"After that, I think I played better," said Nadal, adding that one benefit of the tough match was that it showed him the back trouble that hindered him in his Australian Open loss to Wawrinka -- and which was still nagging him when he won in Rio last month -- needn't worry him.
"Probably that match is going to help me understand that I really can start to serve normal again," he said.
For Murray, early struggles at Indian Wells are nothing new.
Murray reached the final on the hardcourts of the California desert in 2009, but he had lost his openers in two of the past three years.
"Today, I was a set and a break down," he said. "I got broken three times in a row at the end of the first set, beginning of the second. You know, I just kind of kept going and found a way to win, which is always the most important thing."
Colombia's Alejandro Falla came back from 2-5 down in the third set to beat 18th-seeded Jerzy Janowicz of Poland 6-3, 2-6, 7-6 (7/5), saving one match point on the way.
Falla will take on Canadian Milos Raonic, who pounded 33 aces past France's Edouard Roger-Vasselin in a 7-6 (7/4), 4-6, 7-6 (7/2) victory.
In women's action, top seed Li Na, who won her second Grand Slam title at the Australian Open in January, won an all-Chinese clash with Zheng Jie 6-1, 7-5.
Fourth-seeded Russian Maria Sharapova got her title defence off to a strong start with a 6-1, 6-4 victory over Germany's Julia Goerges.
"I thought I did what I had to do," said Sharapova, a former world number one who is trying to reach her first final of 2014.
Results on Saturday from the ATP Masters and WTA BNP Paribas Open (x denotes seeding):
Rafael Nadal (ESP x1) bt Radek Stepanek (CZE) 2-6, 6-4, 7-5
Alexandr Dolgopolov (UKR x28) bt Tim Smyczek (USA) 7-6 (7/3), 6-4
Gael Monfils (FRA x23) bt Sergiy Stakhovsky (UKR) 6-2, 6-4
Fabio Fognini (ITA) bt Ryan Harrison (USA) 5-7, 6-1, 6-4
Milos Raonic (CAN x10) bt Edouard Roger-Vasselin (FRA) 7-6 (7/4), 4-6, 7-6 (7/2)
Alejandro Falla (COL) bt Jerzy Janowicz (POL x18) 6-3, 2-6, 7-6 (7/5)
Jiri Vesely (CZE) bt Pablo Andujar (ESP x32) 6-1, 2-6, 6-1
Andy Murray (GBR x5) bt Lukas Rosol (CZE) 4-6, 6-3, 6-2
Stanislas Wawrinka (SUI x3) bt Ivo Karlovic (CRO) 6-3, 7-5
Andreas Seppi (ITA x29) bt Sam Querrey (USA) 4-6, 7-6 (7/3), 6-3
Kevin Anderson (RSA x17) bt Lleyton Hewitt (AUS) 7-6 (7/5), 6-4
Evgeny Donskoy (RUS) bt Michael Russell (USA) 6-4, 6-3
Tommy Haas (GER x11) bt Jeremy Chardy (FRA) 6-3, 6-4
Kei Nishikori (JPN x19) bt Santiago Giraldo (COL) 6-1, 6-3
Dmitry Tursunov (RUS x27) bt Juan Monaco (ARG) 7-6 (7/4), 6-4
Roger Federer (SUI x7) bt Paul-Henri Mathieu (FRA) 6-2, 7-6 (7/5)
Li Na (CHN x1) bt Zheng Jie (CHN) 6-1, 7-5
Karolina Pliskova (CZE) bt Klara Zakopalova (CZE x28) 7-5, 6-2
Anastasia Pavlyuchenkova (RUS x21) bt Caroline Garcia (FRA) 6-4, 7-5
Aleksandra Wozniak (CAN) bt Sabine Lisicki (GER x15) 7-5, 1-6, 7-6 (7/5)
Dominika Cibulkova (SVK x12) bt Donna Vekic (CRO) 6-3, 6-2
Ekaterina Makarova (RUS x23) bt Monica Niculescu (ROM) 5-7, 7-6 (7/3), 6-3
Svetlana Kuznetsova (RUS x27) bt Barbora Zahlavova Strycova (CZE) 6-3, 6-3
Petra Kvitova (CZE x8) bt Coco Vandeweghe (USA) 6-1, 6-3
Maria Sharapova (RUS x4) bt Julia Goerges (GER) 6-1, 6-4
Camila Giorgi (ITA) bt Sorana Cirstea (ROM x25) 7-6 (7/3), 6-3
Flavia Pennetta (ITA x20) bt Taylor Townsend (USA) 6-3, 6-7 (4/7), 6-3
Samantha Stosur (AUS x16) bt Francesca Schiavone (ITA) 6-2, 6-3
Ana Ivanovic (SRB x11) bt Elina Svitolina (UKR) 4-6, 7-5, 7-6 (7/1)
Sloane Stephens (USA x17) bt Ajla Tomljanovic (CRO) 6-4, 6-0
Alisa Kleybanova (RUS) bt Garbine Muguruza (ESP x32) 6-3, 6-2
Maria Teresa Torro (ESP) bt Angelique Kerber (GER x5) 2-6, 7-6 (7/5), 6-4