Reigning champion Novak Djokovic was an easy second-round winner on a hot Friday at the U.S. Open.

The second-seeded former world No. 1 star drubbed Brazil's Rogerio Dutra Silva 6-2, 6-1, 6-2 in 1 hour, 39 minutes at Ashe Stadium, where the temperature was above 90 degrees.

Djokovic currently holds two of the four Grand Slam titles, as he also won this year's Australian Open in addition to his 2011 U.S. Open championship when he beat Rafael Nadal in the final at the USTA Billie Jean King National Tennis Center.

The five-time major champion is also a two-time U.S. Open runner-up (2007, 2010).

Spanish star David Ferrer was also a second-round winner on Day 5.

The fourth seed moved on in straight sets against Dutchman Igor Sijsling, but the tight third went to a tiebreak, as the gritty Spaniard settled for a 6-2, 6-3, 7-6 (14-12) decision on the Grandstand court.

Ferrer advanced in 2 hours, 27 minutes, breaking Sijsling four times en route to the round of 32.

Nifty 13th-seeded Frenchman Richard Gasquet moved on by easily beating Stanford University's Bradley Klahn 6-3, 6-3, 6-1.

Meanwhile, 22-year-old American Steve Johnson reached the third round by overcoming talented Latvian Ernests Gulbis 6-7 (3-7), 7-6 (7-5), 6-3, 6-4. Gulbis launched 24 aces in a losing effort.

The former USC Trojan Johnson is the two-time reigning NCAA singles champ.