PHOTOS: Misfiring Nadal reaches last 16 at Indian Wells

A misfiring Rafael Nadal had trouble hitting the mark but the third seeded Spaniard still had enough to beat American Donald Young 6-4, 6-2 on Tuesday and advance to the fourth round of the BNP Paribas Open.

Roger Federer earned a modicum of revenge against Andreas Seppi in a 6-3, 6-4 triumph that advanced the four-time champion to the fourth round of the BNP Paribas Open on Tuesday.

Federer lost to the Italian at the Australian Open in January but allowed no such repeat as he lost just one service game and needed 82 minutes to beat Seppi and advance to fourth round.

Nadal, a three-time champion at Indian Wells, looked out of sorts in a sloppy opening set slamming an easy overhead into the net to give Young an early break and then later double-faulting to hand over another.

But the 47th ranked Young was no better at finding the target saving just two of eight break points as a fist-pumping Nadal walked off Stadium court at the Indian Wells Tennis Garden with the victory.

While the opening set was a comedy of unforced errors the second saw Nadal flash some of his top form as he raced to a 5-1 lead closing out the match in a tidy 80 minutes.

Ninth seeded Czech Tomas Berdych had earlier kicked off another sunny day of action with a straight-forward 6-4, 6-2 win over American Steve Johnson.

Jack Sock, however, will carry the American flag into the round of 16 after rallying past 15th seeded Spaniard Roberto Bautista Agut 3-6, 6-3, 6-2.

Thirteenth seeded Frenchman Gilles Simon scored a comfortable 6-2, 7-5 victory over German qualifier Michael Berrer while Czech Lukas Rosol was a 6-4, 6-7 (4), 7-6 (3) winner over Dutchman Robin Haase.

Serena overcomes slow start to reach quarters

Top seed Serena Williams overcame a wobbly start to see off a determined Sloane Stephens 6-7 (3), 6-2, 6-2 on Tuesday and advance to the quarter-finals of the BNP Paribas Open.

Maria Sharapova fell victim to an emotional Flavia Pennetta, who burst into tears before regaining her composure to stun the second seed 3-6, 6-3, 6-2 at the BNP Paribas Open on Tuesday.

Italy's Pennetta, the defending champion at Indian Wells, left the court momentarily after breaking down following her first set loss. "Sometimes woman have these moment. (I) just go and let everything out, screaming..." Pennetta told reporters.

"I just breathe and just let it pass."

When the 15th seeded Pennetta returned she seized the momentum, going on to win 10 of the last 13 games to blaze past the two-time champion Sharapova and into the last eight.

Sharapova said she was unaware of Pennetta's emotional outburst and had struggles of her own, the Russian finishing with 42 unforced errors and 11 double faults.

"Maybe I wasn't playing my best tennis but I was competitive enough," Sharapova said. "I just wasn't able to step up in the key moments."

Williams, playing her third match at Indian Wells after deciding to end a 14-year boycott of the event where she had suffered alleged racist abuse, enjoyed plenty of support but struggled early to find her form.

Stephens, who reached the quarter-finals a year ago, looked ready to return to the last eight after breaking Williams twice to open the match but in the end there was no denying Williams as she extended her winning run to 14 matches.

"I don't feel like I need to come here and win the trophy," Williams told reporters.

"I feel like this is more than I have ever imagined doing. I never imagined even having an opportunity to come back.

"I feel like I have been a champ here, and I'm really happy with every match that I win and every result. For me it's all icing on the court."

On another sun-bathed afternoon Stephens got the contest off to a bright start charging in front 3-0.

But Williams, who has not lost since last year's WTA Finals in Singapore, quickly got her game in gear sweeping through the next four games before her opponent could again hold serve.

Displaying plenty of grit of her own, Stephens dug in to force the opening set to a tiebreak that she dominated.

Playing with a greater urgency, Williams broke Stephens to open the second and would break her compatriot again to go up 5-2 before serving out the set to level the match.

The third set followed a similar script as Williams, playing her first event since winning her 19th grand slam title, and sixth at the Australian Open, recorded the early break to secure a 2-0 advantage. She broke again in the seventh game and held serve to close out a challenging test in two hours, six minutes.

"I thought I played a really solid first set," said Stephens.

"Obviously I was playing the number one player in the world so it was going to be a little tough."

In other matches, third seeded Romanian Simona Halep rolled past 14th seeded Czech Karolina Pliskova while 12th seeded Spaniard Carla Suarez Navarro be Briton Heather Watson.