The second-seeded Spaniard, playing just his third tournament since Wimbledon due to a wrist injury, blasted past Herbert in 57 minutes, breaking the qualifier's serve five times.
Nadal, who struggled with appendicitis earlier this month in Shanghai, was never troubled by the 120th-ranked Herbert, who double-faulted 11 times.
Nadal did save two break points, including when he was serving for the match. He next plays either Andrey Golubev of Kazakhstan or 17-year-old Croatian wild card entry Borna Coric on Wednesday. Both won their first-round matches.
Coric, ranked 124th, caused a big first-round upset when he beat sixth-seeded Ernests Gulbis of Latvia 7-6 (2), 6-3.
Although the 13th-ranked Gulbis, this year's French Open semifinalist, had nine aces, he constantly felt the pressure of Coric's excellent return. He faced 14 break points in the match, dropping his serve three times.
Golubev won 6-3, 6-3 against Teymuraz Gabashvili of Russia.
Meanwhile, Denis Istomin of Uzbekistan had 14 aces as he reached the second round with a 6-1, 6-1 rout of Poland's Jerzy Janowicz, a renowned server who managed only two aces and lost his serve five times.