Twenty-nine-year-old Ovtcharov beat Japan's Koki Niwa, a silver medalist in the team event at Rio 2016, by a score of 10-12, 11-6, 12-14, 9-11, 11-9, 11-5 in their round-of-16 match to secure his place as world number one for the first time in his career.

The current men's World Cup champion will overtake world and Olympic champion Ma Long of China, who has been top of the ITTF World Rankings for 34 consecutive months.

Ovtcharov will be the first number one under the new ITTF world ranking system, which "aims to present a more accurate measure and realistic situation of the playing level and to ensure that the world ranking better supports ITTF events".

Speaking after his victory against Niwa at the Daulet Sport Complex, Ovtcharov said: "World number one sounds unreal.

"I have been dreaming about it since I started playing, but we have millions of players around the world working hard, and they will soon be able to see my name on the top of the list.

"This makes me proud and I'm very thankful to everyone who has supported me throughout my entire career.

"I'm really stressed, my wife asked me a few times if I'm with her in one world or in my own world and it was really good to have her with me to keep my mind clear.

"It was a tough match and he's a very tough opponent.

"Actually, it feels like this tournament is a new start for me and I need to refresh my mind.

"I'm saying to myself 'Dima, it's the Grand Finals, you have to play round by round, the first round is not the final'.

"There are four more matches to go and you can win the tournament.

"But it’'s still hard to change your mindset and I'm glad to make it through."

Elsewhere, two quarter final matches were completed in the men's draw.

Fan Zhendong knocked out Xu Xin in an all Chinese affair, 11-6, 11-8, 9-11, 11-9, 11-10.

Germany's Timo Boll then battled past Hong Kong's 4-11, 11-8, 9-11, 11-3, 11-9, 11-3.

The women’s singles draw is set for an all-Chinese semi-final following wins for Gu Yuting and Chen Meng.

Gu, who has 12 world junior titles to her name, faced Kasumi Ishikawa in the quarter-finals and came out on top 6-11, 11-9, 11-8, 11-6, 6-11, 11-4.

The fifth seed from China had been left frustrated in the first game after missing out on an edge decision at 7-5 down, allowing two-time Olympic medalist Ishikawa to go on and take the game.

However, Gu did not let this bother her and she went on to claim the next three consecutive games.

Although Ishikawa cut the deficit down in the fifth game, Yuting went on to claim her place in the semi-finals in the sixth with an 11-4 win.

After her win, the 22-year-old said: "This is my first World Tour Grand Finals appearance so I'm really happy to be able to make the semi-finals this time.

"I have no worries for the next few matches already, so I can just play my game and do my best."

Gu will now face Chen in the final four after she pulled off a comfortable victory against eighth seed Feng Tianwei of Singapore, who won two bronze medals at London 2012, 11-4, 11-8, 11-6, 11-3.