London: Jack Sock booked a place in the semi-finals of the ATP Finals with a surprise 6-4,
1-6, 6-4 win over German prodigy Alexander Zverev, while title favourite Roger Federer
warmed up for the last four by subduing Marin Cilic on Thursday.
Sock is the first American to reach the semi-finals of the season-ending event since Andy
Roddick in 2007.
The 25-year-old, up to a career high ninth in the world rankings, only qualified for the
Tour Finals thanks to his first Masters title in Paris earlier this month.
Jack Sock of the United States celebrates after defeating Alexander Zverev of Germany in
their men's singles tennis match at the ATP World Finals at the O2 Arena in London,
Thursday, Nov. 16, 2017. (AP Photo/Alastair Grant)Jack Sock celebrates after defeating
Alexander Zverev in the ATP World Finals. AP
Sock was so sure he wouldn't make it to the O2 Arena that he had planned to play a round of
golf at Augusta this week.
Instead of working on his putting, Sock ground out a hard-fought victory over third seed
Zverev, securing second place behind Federer in the Boris Becker group and a Saturday
semi-final date with Pete Sampras group winner Grigor Dimitrov.
"That was a rollercoaster match. I didn't have the hottest start in the third but I kept in
there and kept fighting," Sock said.
Dimitrov, who takes on Pablo Carreno Busta on Friday, qualified for the last four after
winning his first two matches.
Federer's opponent will be either Belgian David Goffin or Austria's Dominic Thiem, who
clash in a winner-takes-all Sampras group tie on Friday.
Just four months ago and only a few miles across south London, Federer was celebrating his
record eighth Wimbledon crown after crushing Cilic in a brutally one-sided final.
Cilic had been hampered by a blistered foot and the Croat was reduced to tears during the
match as his predicament sunk in.
In their first meeting since that All England Club showdown, Federer frustrated the already
eliminated Cilic once again as he fought back to win 6-7 (5/7), 6-4, 6-1.
By extending his current winning streak to 13 matches, the 36-year-old advanced from the
Tour Finals group stage with an unblemished 3-0 record for the 10th time in his glittering
With Andy Murray, Novak Djokovic and Stan Wawrinka all absent due to injury and World No 1
Rafael Nadal withdrawing after his first match due to a knee problem, Federer appears to
have a clear path to his seventh triumph in the season-ending event.
"It was a tough match. I was in trouble, a set and a break point down, but I found a way
out of it and I'm happy to be playing this way," Federer said.
"It's nice to play tennis this freely. It gives me a great idea how I want to be on
Saturday. I'm looking forward to facing (David) Goffin or (Dominic) Thiem."
The prize money from Federer's win over Zverev on Tuesday took him past golfer Tiger Woods
to become the world's highest earning athlete, with a career total of £84 million ($110
million, €94 million) according to Forbes.
But Federer is motivated by his legacy rather than the size of his bank balance.
Winning the Tour Finals for the first time since 2011 would be another feather in his cap
at the end of a remarkable renaissance year, which has seen him capture seven titles.
Zverev is tipped as a possible heir to Federer's throne, but the 20-year-old still has work
to do after an erratic display against Sock.
A bruising first set went in Sock's favour before Zverev took the second with ease.
When Zverev maintained his assault with a break in the first game of the deciding set, Sock
smashed the ball into the crowd with such force that he was punished with a penalty point.
Sock channelled that rage with a burst of power hitting as he won four successive games.
In a dramatic finish, Zverev roared back from 4-1 down to draw level, only for Sock to
pounce on his first match point.