Rafael Nadal declared himself happy with his recovery from injury as he breezed into the last 16 of the BNP Paribas Open.
Nadal had no trouble in routing Croatian Mario Ancic 6-2 6-2 as he continued his comeback from a knee injury which had sidelined him since the quarter-finals of the Australian Open at the start of the year.
The Spaniard was not required to deal with a break point and prevailed four times on Ancic's normally formidable serve.
He will next face the 15th seed John Isner, who prevailed 7-6 (7/3) 6-4 in an all-American clash with Sam Querrey.
"Coming back from an injury you have to start slowly," Nadal told Sky Sports 2.
"But I am pleased with the way I am playing, and I am in the next round so that is the important thing."
He added: "I am playing at the good level with my forehand when I touch the ball all the time.
"I try to do something - playing aggressive, playing long, changing the direction - so that's very important."
Second seed Novak Djokovic was forced to battle through a final-set tie-break to reach the last 16.
All seemed to be going to plan for the Serbian as he took the opening set 6-3 with a solitary break, but Kohlschreiber upped his first-serve percentage to 73% in the second and broke three times to take the set 6-2 and level the match.
Two breaks apiece saw a topsy-turvy third set go the distance, but Djokovic prevailed 7/3 in the tie-break to clinch victory in two hours and 35 minutes.
Tenth-seeded Fernando Verdasco of Spain was a high-profile victim as he crashed out 6-0 6-3 at the hands of 19th-seeded Czech Tomas Berdych in 59 just minutes.
Berdych now meets Viktor Troicki of Serbia, seeded 29, who enjoyed a walkover win on Sunday due to Nikolay Davydenko's broken wrist.
Eleventh seed Juan Carlos Ferrero crashed out in three sets to Juan Monaco.
The Argentinian, seeded 21st, took the opener on a tie break and, after Ferrero levelled courtesy of his only break, he responded to win 7-6 (7/2) 3-6 6-3.
Guillermo Garcia-Lopez of Spain defeated 26th-seeded Brazilian Thomaz Bellucci in three sets, 4-6 6-2 6-1, while Ivan Ljubicic, the 20th seed from Croatia, was a 6-2 6-3 winner over Argentinian qualifier Brian Dabul.