NEW YORK - Serena Williams won the last eight games straight to reach the US Open's fourth round with a 6-4 6-0 victory over Russia's Ekaterina Makarova.
The fourth-seeded Williams hit eight aces and won 32 of the 40 points she served on Saturday.
The match was even at 4-all in the first set, when Williams broke the left-handed Makarova, who upset the American at the Australian Open earlier this year, for the first time to seize control in Arthur Ashe Stadium.
Williams' fourth-round loss to Makarova in Melbourne is the only defeat in 22 Grand Slam matches against lefties for the 14-time major champion.
This time, though, Williams built a 31-10 edge in winners and moved a step closer to a fourth US Open title.