India registered a big upset in men's basketball when they beat China, the top-ranked Asian team, 70-64 in the FIBA Asia Challenge Cup at the Azadi Indoor Stadium in Tehran on Tuesday.

The Chinese, ranked 14th in the world, hadn't lost a single match in the tournament till that point and had won their previous three matches comfortably.

The 53rd-ranked Indians, on the other hand, had a mixed tournament beating Philippines, ranked 27th, but losing to Chinese Taipei (48) and Jordan (28).

Precursor to the FIBA Asia Championship

The purpose of the FIBA Asia Challenge Cup is to allocate berths to sub-confederations for the 2017 FIBA Asia Cup, the continental tournament for international basketball.

This is the sixth edition of the tournament, and India had finished seventh in the last edition. China are the defending champions.

The top five teams will earn their respective sub-confederations an additional berth for the FIBA Asia Cup. Currently, FIBA Asia is split into the six respective sub-confederations: Central Asia, East Asia, Persian Gulf, South Asia, Southeast Asia and West Asia.

In case more than one team from the same sub-confederation finishes in the top five, that sub-confederation receives the additional berth for next year's Asia Cup.

Format of the Challenge Cup

Twelve teams had qualified for the Challenge Cup, with one slot from Southeast Asia going to India, after they won the 2016 South Asia Basketball Association (SABA) held in Bengaluru earlier this year. India defeated Maldives, Nepal and Bangladesh on their way to the SABA title.

The twelve teams are split into four preliminary groups of three each and all teams go through to the next round, the preliminaries being used as ranking rounds instead of knockouts.

India, placed in Group B with Chinese Taipei and Philippines lost against the former and beat the latter to finish their group engagements on three points. Teams are awarded two points for a win and one point for a loss.

In the second round, Groups A and B are combined into one Group E and so are Groups C and D into Group F. Teams face the three countries from the group that they were not placed in - hence, India faced the teams from Group A - Jordan, China and Kazakhstan.

The top four teams from each group qualify for the quarterfinals and the other teams play for places 9-12.

India's chances

India's win over China has really boosted their chances of a quarter-final finish at this year's tournament. Ahead of their final group stage engagement against Kazakhstan, India lie in fourth and the final qualifying spot in Group E with six points from two wins and two losses.

They face the Central Asian nation, who are ranked 56th and lie last in their group with four points from four losses. They have an identical points difference (PD) of -66, which means that the winner of this match qualifies for the quarter-finals.

If India win, it is highly unlikely that they will be able to leapfrog the loser of the match between China and Chinese Taipei, who are both on seven points. This is because China and Chinese Taipei have PD's of +43 and +24, and India would have to effect a 90 point-swing at the very least between themselves and the loser of the China-Chinese Taipei match.

Should India qualify for the quarters, they will face the winners of the match between Iran (ranked 25th) and South Korea (ranked 30th), who lie first and second in Group F currently.

This will prove a tough challenge to the Indian team as both are strong teams and are yet to lose a match in this year's competition so far.