Novak Djokovic wobbled but avoided joining Rafael Nadal in making an early exit from the BNP Paribas Open.
Stanislas Wawrinka aside, the top men have been finding life rather difficult in the Californian desert, capped by world number one Nadal's shock loss against Alexandr Dolgopolov on Monday evening.
Fourth seed Tomas Berdych lost his first match and Andy Murray scraped through an ugly clash with Jiri Vesely on Monday, while Juan Martin del Potro did not even take to the court because of injury.
Djokovic headed to Indian Wells without a title for the first season since 2006 and question marks remain about his form after a 6-1 3-6 6-1 win over world number 91 Alejandro Gonzalez.
The 25-year-old had never won a main-draw match on the ATP Tour before this week but caused Djokovic plenty of problems. And the Serb is likely to have to raise his level if he is to make the quarter-finals, with in-form Marin Cilic up next.
The Croatian has blossomed since hiring Goran Ivanisevic as his coach ahead of the start of the season and Tuesday's 6-4 6-3 win over Tommy Robredo was his 20th of the year.
There may be no Nadal any more, but three Spanish men are in the last 16. Fernando Verdasco was the most impressive on Tuesday, beating eighth seed Richard Gasquet 7-6 (7/5) 6-1 while Berdych's conqueror Roberto Bautista Agut and Feliciano Lopez are also through.
In the women's tournament, last year's runner-up Caroline Wozniacki was well beaten by seventh seed Jelena Jankovic.
Wozniacki led 3-1 in the opening set but Jankovic reeled off 10 games in a row before going on to win 6-3 6-1.
Jankovic had lost her previous five matches against Wozniacki, with her last win coming in Indian Wells four years ago.
The Serbian struggled with a back problem in her first match, and she said: "I was pretty pleased with the way I played and how composed I stayed throughout the whole match.
"I kind of surprised myself, especially because of my back. Two nights ago I hurt my back, and yesterday did not hit at all. I had a lot of treatment, I could not put my shoes on and all these kind of things.
"So I went on court today not knowing how I was going to feel."
Top seed Li Na of China advanced to the quarter-finals with a 6-1, 6-4 victory over Canada's Aleksandra Wozniak to set up a rematch with the woman she defeated in the final at Melbourne, Dominika Cibulkova.
The Australian Open finalist beat eighth-seeded Petra Kvitova 6-3, 6-2.
Simona Halep won the battle of the rising stars against Eugenie Bouchard 6-2 1-6 6-4 to reach the quarter-finals.
Australian Open semi-finalist Bouchard broke serve to lead 4-3 in the decider but Halep hit back with three games in a row.
The Romanian won more singles titles than any woman except Serena Williams last season and has carried the momentum into 2014.
Bouchard had suffered three losses to lower-ranked players since her run in Melbourne so felt she had got back on track.
The 20-year-old said: "I think I've improved since Australia. I feel like I'm playing at a better level. On the court as well I feel good mentally. It's never a straight road to the top. It's a learning experience."
Sixth seed Halep next meets Australian Casey Dellacqua, who was the beneficiary of American Lauren Davis' withdrawal through illness.
Meanwhile, Maria Sharapova's conqueror Camila Giorgi was brought firmly back down to earth with a 6-2 6-1 hammering by fellow Italian Flavia Pennetta.
