Nitto ATP Finals: Novak Djokovic sweeps aside Alexander Zverev to keep tennis' new generation at bay

After some early resistance, the Serbian world No1 routed the young German in straight-sets

Novak Djokovic will end the year as world No1 (Getty)

Novak Djokovic has 834 Tour match wins in his storied career and the latest, a 6-4 6-1 rout of young German Alexander Zverev at the ATP Finals on Wednesday, will not be one for his scrapbook.

Yet despite him not feeling 100 per cent, it illustrated just how the Serb has become one of the all-time greats, mastering the ability to churn out victories in third gear.

Zverev provided some fierce resistance in the opening set of their round-robin match, but as he so often does Djokovic played the percentages.

Djokovic, who will end the year as world number one for the fifth time, struck only three winners in the opening set but relied on his rock-solid 'middle game' to take the opener.

This was only the third meeting between the pair (Getty)

A demoralised Zverev then fell apart, losing the last five games of a match that petered out into another one-sided affair -- the pattern so far at the O2 Arena this year where the opening seven matches have not provided a single three-setter.

"I guess winning the first set really counts this year. Then, I guess, you have mentally quite an edge," Djokovic said.

Djokovic has now won 33 of his last 35 matches and looks unstoppable as he seeks a sixth ATP Finals title.

With two easy wins so far in the Gustavo Kuerten group, he will advance into the last four of the season-ending tournament for the eighth time if American John Isner beats Marin Cilic in the battle of the big servers later. The top seed will also reach the semis if Cilic beats Isner in three sets.

"It wasn't a great quality tennis match, to be honest, at least from the court," Djokovic, who was coughing occasionally and grabbing a tissue from his pocket, told reporters.

"Somehow I managed to gather the strength when I needed it. I think also it seemed like Sascha was not feeling really great, definitely not playing well, especially from the back of the court. He made a lot of errors."

For a while, at the start of the match, it seemed ticket holders might be in for a treat.

Zverev, who has a Tour-leading 55 match wins this year, went toe-to-toe with Djokovic from the baseline and looked to have the baseline firepower to worry his opponent, striking 15 winners in the opening set.

Djokovic has now won 33 of his last 35 matches (Getty)

Djokovic netted a routine forehand when serving at 4-4 30-30, offering Zverev a breakpoint that he did not convert.

Djokovic then double-faulted to give Zverev another chance to serve for the set but this time the German went just wide with an attempted lob after the Serb ventured into the net.

The next game always looked dangerous for Zverev and so it proved as he double-faulted to concede the set.

Zverev looked deflated and despite holding serve for 1-1 he offered no more resistance as Djokovic won five games in a row.

It is not all over for Zverev who can still reach the semi-finals for the first time if he beats Isner on Friday.

"I think I'll take it as a normal quarter-final match at a normal tournament," said the German, who beat Cilic in his opening match on Monday.

"To be in the semi-finals here would mean a lot to me. For that, I have to play good tennis."

Reuters