North and South Korea clash on the football pitch and India do battle with Pakistan in hockey as fierce rivalries take centre stage at the Asian Games on Saturday.

The men's and women's 100m sprint titles will also be contested on the athletics track in Hangzhou, where the rain fell steadily in the early afternoon.

With the Games approaching their halfway point, hosts China have raked in 107 gold medals, far ahead of the rest, with Zhang Zhizhen doing his part on Saturday by winning the men's tennis crown.

The 60th-ranked Zhang made a slow start and fell 4-1 behind in the first set of the final against Japan's Yosuke Watanuki.

But with the home crowd roaring him on, the 26-year-old from Shanghai battled back to win 6-4, 7-6 (9/7) and become the first Chinese men's singles tennis champion at the Games since 1994.

"It's been a very, very tough week, not just this match, but very tough for the whole week actually, from the first match onwards," said Zhang.

"But I'm super-happy that from the beginning of the first match, step by step, I've played better and better tennis."

Earlier in the day, Taiwan's Chan Hao-ching and Chang Yung-jan won gold in women's doubles. The second-seeded pair beat fellow Taiwanese Lee Ya-hsuan and Liang En-shuo 6-4, 6-3.

Rising Chinese star Zheng Qinwen won the women's singles title on Friday.

Some of Saturday's most mouthwatering match-ups come later in the day.

North Korea and South Korea face off for a place in the semi-finals of the women's football, with local and regional bragging rights at stake between two countries that are still technically at war.

Also in the last eight, holders Japan play the Philippines, China face Thailand and Taiwan meet Uzbekistan.

Towards the end of another packed schedule, arch-rivals Pakistan and India face off in a men's hockey group match, in what is sure to be another fierce encounter between neighbours with fraught ties.

Gold medals will be won on Saturday in other sports, including weightlifting, diving, shooting, table tennis and eSports.

Diving, which is expected to be dominated by the home nation's world-class squad, and weightlifting get under way for the first time at these Games.

The drizzle could be a factor in the outdoor sports.

As well as the 100m titles, five other golds will be snapped up on the second day of track and field.

EJ Obiena of the Philippines, the world number two, will be hot favourite to clinch a first Asian Games gold of his career in the pole vault.