Six-time champion Serena Williams shook off a sluggish start to power past eighth-seeded Karolina Pliskova 6-4, 6-3 on Tuesday and into the US Open semi-finals.
The US superstar, chasing a record-equalling 24th major title, surrendered an early break to Pliskova, but she roared back with a streak of eight straight games to put away the opening set and take a 4-0 lead in the second against the woman who beat her in the semi-finals at Flushing Meadows in 2016.
“Well I don’t know,” Williams said of how she engineered the turnaround.
“The crowd was really rooting for me and I felt so bad because everyone out here was cheering and I wasn’t winning and I thought I’ve got to try harder.”
She finished the match with 13 aces and will take on Anastasija Sevastova for a place in the final after the 19th-seeded Latvian toppled defending champion Sloane Stephens 6-2, 6-3.
There was a wobble for Williams as she dropped her serve in the second set, coughing up one of her five double faults on break point as Pliskova narrowed the gap to 4-1.
Williams fell behind again in the seventh game, but erased a 0-40 deficit with a 112 mph (180 Km/h) service winner followed by a another service winner and an ace.
Pliskova got another chance when Williams batted a forehand into the net, but another booming serve, a backhand winner and an unreturnable serve saw her negotiate the danger.
Serving for the match at 5-3 Williams didn’t allow any room for doubt, holding at love with two aces and an overhead smash followed by one last ace.
“I really feel like right now I’m playing free because I was having a baby this time last year, so I have nothing to prove,” said Williams, who is seeking her first major title since her daughter Olympia was born on September 1 of 2017.
With a win she would break out of a tie with Chris Evert for most US Open titles, and equal Margaret Court’s all-time record for Grand Slams.