Alexander Zverev’s long-predicted arrival at the summit of men’s tennis is taking too long for some impatient observers but he has taken another step forward by beating John Isner to reach the last four at the ATP Finals.
His 7-6 (7-5) 6-3 victory over the American meant the 21-year-old became the first German since Rainer Schuettler in 2003 to reach the semi-finals of the prestigious year-ending tournament and the youngest since Juan Martin del Potro in 2009.
Zverev’s second group victory earned him the runner-up spot behind Novak Djokovic and he will now aim his range of baseline weapons at six-times champion Roger Federer on Saturday on one of the sport’s biggest stages.
“It’s obviously great getting to the semi-finals. But the tournament isn’t over,” Zverev said.
“There’s only good opponents left. There’s only the best in the world.”
The other semi-final will be between five-times champion Djokovic, who beat Zverev comfortably this week, and South African debutant Kevin Anderson.
Djokovic was in action later on Friday against Croatian Marin Cilic but Zverev’s win made that tussle academic, apart from the 200 ranking points and $US200,000 ($A275,380) on offer for each round-robin win at the event.
While not a Grand Slam tournament — of which Zverev is yet to go beyond the quarter-finals stage — the ATP Finals are regarded in some quarters as a fifth major.
And the floppy-haired, gold chain-wearing Zverev looked every bit a real contender for the game’s biggest prizes as he fired down 140mph serves and thrilled the packed crowd with spectacular groundstrokes, especially from his lethal backhand.
One Hollywood effort early in the second set, struck for a clean winner from almost in the front row seats, revealed the showman in Zverev as he conducted the rapturous applause.
There have been questions about his mental toughness including last year in London when a loss to Jack Sock cost him a semi-final berth. But with Andy Murray’s former coach Ivan Lendl and strength conditioner Jez Green now in his team Zverev appears to have a tougher streak.