Novak Djokovic passed a tough first test at Indian Wells on Sunday to maintain his perfect record for the season and reach the third round of the year's first Masters tournament.
The world No. 1 defeated 36th-ranked Fabio Fognini 6-0, 5-7, 6-2.
But he was kicking himself for letting control of the match slip away in the second set, when he went up an early break only for Fognini to get back on serve with a break of his own in the seventh game.
"It was definitely a difficult challenge today," Djokovic said. "Fabio played well towards the end of the second set, but it was all my fault. I had a break for 4-2 up and I played a terrible game.
"After that it was very even. It could have gone either way."
Fognini saved a match point with a service winner in the the 10th game of the second set and broke Djokovic in the 11th.
He duly served out the set, and had Djokovic under pressure in the opening game of the third, when the Serbian fended off one break point then battled through four game points and an irksome time violation before finally holding serve.
From there Fognini began to flag. Djokovic held with ease for a 2-1 lead, then broke Fognini for 3-1. Fognini saved another match point with a service winner in the final game before Djokovic sealed the win.
Djokovic said his difficulties hadn't dented the confidence gained from capturing his fourth Australian Open crown in January, and a fourth Dubai Open title last week.
"I'm not concerned," Djokovic said. "I know I have been in this situation before where I had minor setbacks in a match, especially in the opening matches where I'm trying to get used to the court, the conditions, so forth.
"In the end, I have done what I needed to do. The 'W' is there, so I feel good about myself."
World No. 3 Andy Murray started slowly but came on strong in a 5-7, 6-2, 6-2 victory over Russian Evgeny Donskoy.
Murray admitted to some first-match nerves, partly because he was playing in his first match since falling to Djokovic in the Australian Open final and partly because he fell in his first match here in each of the past two years.
Murray found himself in a 5-1 hole in just 24 minutes against Donskoy, a 22-year-old ranked 83rd in the world.
The Scot won four straight games to knot the set. However, he was unable to convert any of six break chances in the 11th, and Donskoy broke him for a third time in the 12th game to pocket the set.
Murray, however, had found his range and made short work of the second and third sets.
It was a bit of a slog for the top women in action on Sunday as well.
Second-seeded Russian Maria Sharapova had to battle back from an early break en each set to earn a 7-5, 6-3 third-round victory over Spain's Carla Suarez Navarro.
"I thought it was a tough one," Sharapova said. "She's a quality player, capable of playing some really good tennis. She's beaten top players in Grand Slams before and has a really solid game with a lot of variety, and she can hit the ball as well.
"There are a few things I want to improve on, but I was happy I got through on not a great day," she added.
Third-seeded Agnieszka Radwanska of Poland rallied after losing a first-set tiebreaker to beat Romanian Sorana Cirstea 6-7 (3/7), 6-3, 6-4.
Fifth-seeded Czech Petra Kvitova, the 2011 Wimbledon champion, needed a second-set tiebreaker to subdue Ukrainian qualifier Lesia Tsurenko 6-2, 7-6 (7/5).
In contrast, sixth-seeded Italian Sara Errani sailed through, defeating Sweden's Johanna Larsson 6-3, 6-1.