Chung taking new rules in his stride in Milan

MILAN, Nov 8 (Reuters) - South Korea's Hyeon Chung maintained his 100 percent record at the Next Gen ATP Finals with a crushing victory over Russian Andrey Rublev on Wednesday to surge ahead in Group A.

Just as he did on Tuesday, the 21-year-old showed a liking for the various new innovations being tested out in Milan as he proved too solid for the higher-ranked Rublev.

World number 54 Chung, easy to spot in his distinctive white spectacles, won 4-0 4-1 4-3(1) to follow up his defeat of Canadian Denis Shapovalov the previous evening.

Chung finished off Rublev in just over an hour, slightly longer than it took Karen Khachanov to beat American Jared Donaldson 4-1 4-3(2) 4-2 in an earlier Group B match.

Donaldson is still without a set after two matches.

"I'm so happy to get my second win here, I had never played Rublev before," Chung told reporters. "I've never played with these rules before, but I like them."

The eight-man tournament, showcasing the leading players aged 21 or under, is using radical new rules aimed at increasing the popularity of tennis.

As well as sets being played only to four games, there are no advantage points, shot clocks, no let serves and coaching via headphones at the end of sets.

Line judges have also been removed for the tournament with Hawk-Eye technology calling lines using an automated voice.

Later on Wednesday Shapovalov takes on home hope and wildcard Gianluigi Quinzi in a clash of former Wimbledon junior champions while Borna Coric faces Russian Daniil Medvedev. (Reporting by Martyn Herman; Editing by Toby Davis)