The younger Williams sister moved her career record to 18-12 in 30 WTA Tour meetings with her older sibling. That includes six consecutive victories in major tournaments since the 2008 U.S. Open with Venus' last triumph coming in the 2008 Wimbledon final.
Serena advances to face Kaia Kanepi in the fourth round.
The 23-time Grand Slam singles champion suffered an injury scare in the second game of the match as she rolled her ankle while trying to make a quick stop. The trainer came out to tape the ankle during the next changeover and it didn't appear to have much of an impact on her movement, though.
That ended up being the only moment of uncertainty during the match.
Serena finished with a 33-14 advantage in winners, 10-1 edge in aces and won 88 percent of the points on her first serve. By contrast, Venus recorded just a single ace, posted more unforced errors than winners and won less than 50 percent of the points on both her first and second serves.
It made for one of the most lopsided matches in their head-to-head history. Venus' total of three games won equaled the lowest amount by either sister when facing each other, matching Serena's 6-1, 6-2 victory in the 2013 Family Circle Cup.
The tournament showcased their post-match embrace:
ESPN Stats & Info provided a note about the younger sister's latest win:
ESPN Stats & Info @ESPNStatsInfo
Serena defeats her older sister for the 11th time in a major. The only women in the Open Era with as many wins in majors against one opponent are: Martina Navratilova - 14 wins vs Chris Evert Serena Williams - 11 wins vs Venus Williams Steffi Graf - 11 wins vs Gabriela Sabatini https://t.co/GYodGaEv01
Serena's victory continued a trend of dominant performances so far in the US Open. She's lost no more than four games in any of her three matches, making her a favorite to take home the women's title next weekend, which would give her seven in the season's final major.
She owns a 4-0 career record against Kanepi, including a straight-sets triumph in the 2014 U.S. Open.