Djokovic broke Anderson's serve once in each set playing in the heat of the day at the Indian Wells Tennis Garden, where he won in 2008 and last year when the Serb claimed three Grand Slam titles and went 70-6. Djokovic successfully defended his Australian Open title to open the year.
Anderson, the 29th seed from South Africa who won last week's tournament in Delray Beach, Fla., managed one break in the first set. Five games went to deuce, including five deuces before Djokovic held to lead 3-2 in the first. Djokovic beat Anderson in straight sets for the fourth straight time.
"He's very aggressive on the return games,'' Djokovic said. "He has a great serve, as you can imagine for his height, so I had to return well, I had to just be patient, and wait for my chances. I haven't served well in the opening set, but then it all came down to his service games. I served well and put a lot of pressure on him and returned really, really good.''
In the day's biggest upsets, No. 6 seed Sam Stosur lost to 30th-seeded Nadia Petrova 6-1, 6-7 (6), 7-6 (5) in a rematch of their three-set U.S. Open marathon last year. That was the longest women's match since the tiebreaker was introduced, with Stosur winning on her way to claiming the title.
On the men's side, Fish was beaten 6-3, 6-4 by qualifier Matthew Ebden of Australia, with Fish getting penalized for hindrance. Roddick lost to No. 7 Tomas Berdych 6-3, 4-6, 6-2. Roddick, seeded 30th, fell to 5-5 on the year, having lost 13 of his last 14 matches against top-10 players.
Roddick had never before dropped a set against Berdych when playing in the U.S. Roddick has been bothered by a right hamstring and right ankle injuries this season.
"I said three or four weeks ago I was going to try not to address it on a daily basis. If you play, you're fine,'' he said. "I played, I competed, and he beat me.''
Big-serving Isner moved on, as did young American Ryan Harrison, who beat Guillermo Garcia-Lopez of Spain 6-4, 7-5 in night's last match.
No. 2-ranked Maria Sharapova defeated Simona Halep of Romania 6-3, 6-4 in their first career meeting. Sharapova is one of three former winners remaining in the field, with Caroline Wozniacki and Ana Ivanovic also in the bottom half of the draw.
Ivanovic rallied to beat Ksenia Pervak, 6-7 (8), 6-3, 6-2 and set up a fourth-round match Tuesday against Wozniacki, who outlasted Sofia Arvidsson 3-6, 7-5, 6-2 in a match that lasted more than 2 1-2 hours. She broke Arvidsson three times in the third set, then closed it out with a forehand winner off the Swede's drop shot.
After a slow start, Sharapova picked up her game in the second set.
"Almost too good, where I felt like I was going for a lot and making a lot of shots. Then felt like I almost started going for a little bit too much,'' she said. "Instead of being patient, putting a few more balls back, I just hit a few errors that I shouldn't have made. I got it together in the end.''
Francesca Schiavone became the eighth player to withdraw because of a viral illness sweeping the Coachella Valley.
The Italian retired after losing the first set 6-2 to Lucie Safarova of the Czech Republic. The tournament's medical provider says the virus causes nausea, vomiting, fever, and diarrhea and is being transmitted by air and direct contact. It is not food-related. Vera Zvonareva also withdrew with a different viral illness.
"Definitely washing my hands as much as possible,'' Petrova said. "I'm going to have a sanitizer in my racket bag. I'm trying to eat outside of the site, so trying to take as many precautions as possible. Gotta be careful.''
Sharapova said she had a similar virus a few years ago.
"It's a great diet, but other than that it's horrible, especially for an athlete,'' she said.
Asked if she was taking precautions, Sharapova joked, "... (if) I have a few extra interviews, I'll be like, `Nah, you know that virus. Might not make it.'''
Petrova had more winners, 15-2, and 15 aces despite not serving as well as Stosur, although the Russian had a pile of unforced errors.
"It was tough battle in the third set, and I was really pumped when I broke her at 6-5 when she was serving for the match,'' Petrova said. "I knew this was my time to win the match.''
Fish was hit with the hindrance rule for yelling, "Come on!'' before Ebden got to the ball after Fish's volley winner in the next-to-last game of the match. It was the same penalty that sent Serena Williams into a rage against an official during the U.S. Open final she lost to Stosur.
Stosur had lunged at a shot but Williams yelled the same thing as Fish before the ball landed. Ebden threw up his hands, clearly annoyed by Fish's outburst.
"It was right under the umpire's nose, so it was pretty clear what happened,'' Ebden said. "I did get there in reasonable time to hit the ball. I still had a decent play on it.''
The International Tennis Federation rule can be interpreted either by giving the point to the opponent if the hindrance was considered deliberate or by replaying the point if the hindrance was considered unintentional. By giving the point to Ebden, chair umpire Felix Torralba interpreted Fish's yell as deliberate interference. Fish refused the traditional post-match handshake with Torralba.
"I don't think it had an effect on him making or missing the shot. But I feel like maybe (play) a let there, unless he hits the shot in. Then that's different,'' said Fish, who was serving. "I've never done that before on tour in my life. I was just trying to fire myself up.''
Other winners Monday were: No. 7 Marion Bartoli, No. 20 Maria Kirilenko, No. 21 Roberta Vinci, No. 12 Nicolas Almagro, No. 13 Giles Simon, and Pablo Andujar.
Top-ranked Americans Bob and Mike Bryan survived a marathon second-round doubles match, beating the Spanish duo of Marcel Granollers and Feliciano Lopez 6-7 (2), 7-6 (4), 17-15.