Milan - Rising star Alexander Zverev dropped by to hit a few balls as the Next Gen ATP Finals showcasing future idols and innovations of tennis got underway in Milan on Tuesday.
Zverev, at 20, should have been among the line-up in the Under-21 version of the ATP Tour Finals, but his stunning season has already earned him a ticket to play with the big boys in London.
He snatched five titles in a whirlwind 2017, brushing aside the likes of Novak Djokovic and Roger Federer. The only survivor was Rafael Nadal who beat the upstart German twice.
"Playing some of the eight best players in the world is very special," said Zverev of next week's London challenge.
"It's going to be an amazing experience after a lot of 'first times' this year."
Zverev was even beginning to sound like a battle-hardened tennis star, when asked to name his idol. "Roger Federer ... I've answered this question about 150 times!" he snapped.
As he plotted his challenge against his childhood heroes - playing just an exhibition game in Milan - a group of eight wannabes were competing for the Next Gen ATP trophy in a tournament with prize money worth $1.275 million with a twist.
Music blasted, strobe lights flashed, players wore headphones to chat to their coaches and checked their stats on a tablet in between sets as the crowd moved around freely during the match.
The pace was fast with no line judges and all calls made using Hawk-Eye Live, no lets, sudden-death points at deuce and a shot clock to ensure a 25-second rule between points to keep things ticking along.
Many of the innovations proved popular as the most promising young players of the season competed in the round robin format with the first to four games in each set winning - a tie-break is used when the scores reach 3-all.
In Group A, South Korea's Hyeon Chung upset Canadian Denis Shapovalov 1-4, 4-3, 4-3, 4-1 as Russian Andrey Rublev outlasted Italian wildcard Gianluigi Quinzi 1-4, 4-0, 4-3, 0-4, 4-3.
In Group B, Daniil Medvedev blasted his way back to beat fellow Russian Karen Khachanov 2-4, 4-3, 4-3, 4-2, with Croatia's Borna Coric easing past American Jared Donaldson (USA) 4-3, 4-1, 4-3.
One of the innovations being tested in Milan - a shorter set - made it tough to wrestle the momentum back once a player was down.
"I lost the first game of the first set and lost the set. It's so fast and very challenging," added Medvedev.
The new format proved key in Chung's victory as big-hitting Shapovalov, at 18 the youngest player in the tournament, struggled with the changes and lost despite blasting down 12 aces to zero for his rival.
"Everything is just different," said Shapovalov. "The court looks different, no lets, roaming in the stands. It's not easy, but I think it's cool to try new things out. I don't think any rule change is easy or hard."
"Many of the rules will never be added but to play this tournament with new rules is great for me," said Medvedev.
"The only thing I didn't like was the crowd they could walk around. It was really tough to focus on the games and your opponent but I liked the other rules."
"I like the shot clock and hawk eye, but as for the other things not sure it's going to happen," added Zverev.
Round robin play continues on Wednesday with the top two from each group progressing to the semi-finals, with the final next Saturday.
Results from the first day of the Next Gen ATP finals Under-21 tournament in Milan on Tuesday:
Hyeon Chung (KOR) bt Denis Shapovalov (CAN) 1-4, 4-3, 4-3, 4-1
Andrey Rublev (RUS) bt Gianluigi Quinzi (ITA) 1-4, 4-0, 4-3, 0-4, 4-3
Daniil Medvedev (RUS) bt Karen Khachanov (RUS) 2-4, 4-3, 4-3, 4-2
Borna Coric (CRO) bt Jared Donaldson (USA) 4-3, 4-1, 4-3
Note: Round robin format, best of five sets but first to four games in each set.