The 16th-seeded Isner beat Kyrgios 7-5, 6-3 in the third-round match.
On Wednesday night, a courtside microphone picked up Kyrgios saying that fellow Australian player Thanasi Kokkinakis had slept with a player who is reportedly Wawrinka's girlfriend.
The ATP fined Nick Kyrgios $10,000 on Thursday, the maximum fine allowed by the ATP rule book for incidents of verbal abuse or unsportsmanlike conduct.
Also, the ATP fined Kyrgios an additional $2,500 for unsportsmanlike conduct related to a comment made to a ball person during the match. The tour said Kyrgios has been served with a "Notice of Investigation," which begins a process to determine if his actions also merit further sanctions.
Djokovic took only 54 minutes to finish off the 35th-ranked Sock.
"I never played him before, so it took me some time to figure out what his patterns are," Djokovic said. "I've watched him many times before, but it's different standing on the court."
The Serb, the tournament champion in 2007, 2011 and 2012, has won 50 of 53 matches this year.
Seventh-seeded Rafael Nadal of Spain beat Russia's Mikhail Youzhny 6-3, 6-3 in a night match. In other late matches, fourth-seeded Kei Nishikori of Japan topped 13th-seeded David Goffin of Belgium 6-4, 6-4, and 10th-seeded defending champion Jo-Wilfried Tsonga of France beat Australia's Bernard Tomic 7-6 (7), 6-3.
Djokovic shut out Sock in the first game. With Djokovic leading the first set 3-2, Sock hit a ball long on break point. Djokovic broke Sock's serve again in the final game to take the set.
"The turning point was the 3-2 game when I made a break," Djokovic said. "After that I just felt in control of the match. I was returning very well. I neutralized his serve, which is one of his biggest weapons."
In the second set, Sock made another unforced error on break point to go down 3-1. Djokovic started the final game of the second set with a beautiful drop shot, and Sock sent his return long on triple match point.