"To me, it's not that surprising", Federer said, as quoted by Sky Sports.
Krajinovic had no answer for Federer's serve or relentless return game and ended up winning just 31 of the match's 93 points.
"It definitely feels like a big deal because I have never gone this far in a tournament", Collins said.
Federer, who is the defending champion and trying to win a record sixth title in the California desert, was on the centre stadium for the third day in a row.
He said playing matches three days in a row doesn't faze him. But I recovered very quickly, and I got myself ready. Daniel plays next Argentinean tennis player Leonardo Mayer. We wait, we play, we wait again, we play again. The Israeli only qualified for the contest as a lucky loser, while Edmund―appearing in his first match since the Australian Open―was widely backed as a dark horse to go deep into the tournament. "I think it was a good match".
His title defence got off to a soggy start on Saturday night when play was suspended because of rain showers with Federer up a set and tied 2-2 in the second.
Merkel elected to fourth term by German parliament
Germany has been locked in political uncertainty for nearly six months after millions of voters abandoned the two main parties. The Social Democrats agreed to join the government only after lengthy internal wrangling.
The 10th-seeded Djokovic acknowledged his poor performance against the world's 109th-ranked player.
Stephens lost to Daria Kasatkina of Russian Federation 6-4, 6-3, and fell to 2-4 in matches this year.
On the men's side, Borna Coric of Croatia upset No. 13 Roberto Bautista Agut of Spain 6-1, 6-3; Jeremy Chardy beat No. 20 Adrian Mannarino 7-5, 4-6, 6-1 in an all-French matchup; and No. 11 Pablo Carreno Busta of Spain defeated Daniil Medvedev of Russian Federation 6-1, 7-5.
South Korea's Hyeon Chung, who surpassed all expectations to reach the Australian Open semi-finals earlier this year, also advanced, taking almost three hours to overcome Dusan Lajovic 6-7 (11/9) 6-3 6-3.
In other action, Croatian Borna Coric defeated 13th seed Roberto Bautista Agut 6-1, 6-3.