One of the few moments of genuine quality came in the breaker.
His victory means the day's second singles between group victor Novak Djokovic and Marin Cilic is academic - apart from ranking points and the $200,000 on offer for each round-robin win at the year-ending showpiece.
Djokovic appeared to be suffering with a cold and grabbed a tissue from his pocket on occasions, but after some fierce resistance in the opening set, he ran away with the match.
Third seed Zverev has won three titles this year, including the Madrid Masters, but although he is often talked about as the leader of the next generation, his record in Grand Slams is poor and he will be desperate to make a statement in London.
"But I don't need to be put in a corner".
The Serbian said of his performance: "The match was great". On Thursday the ATP's chief Chris Kermode and Tennis Australia CEO Craig Tiley, together with ATP Player Council President Djokovic, will hold a news conference in London to launch the World Team Cup which is set to start in January 2020.
Just as in the day's first shootout it was Zverev who jumped into a lead against an edgy Cilic who double-faulted at 1-4.
But this time the German went just wide with an attempted lob after the Serb ventured into the net.
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Zverev was never the same after that.
It seemed to knock the stuffing out of Zverev, who was broken in the fourth game of the second set, and again to love in the sixth.
What had promised to be a real battle petered out into a another one-sided affair and the seventh consecutive group match this year not to go the distance.
Speaking about his chances of winning a 6 ATP World Tour Finals and the group scenario ahead of Wednesday's game, Djokovic said, "I'm feeling fit physically and mentally".
"It's hard to explain how much I loved you and how instrumental you were in making me who I am today". His sole win during the group stage action previous year, however, came over Cilic.
From there Djokovic won the next three games, dropping only one point, as he wrapped up his second win of the week.
John Isner said it had been "very difficult" to focus on his second match at the ATP Finals against Marin Cilic after learning of the death of his close friend and former strength coach Kyle Morgan.
Zverev has one of the most piercing serves in the circuit and has clocked speeds over 130 miles per hour even on second serves. With Cilic serving for the set at 5-3, Zverev broke back before holding serve with an ace to level at 5-5.