China claimed another 13 gold medals - including four in the pool - to surge further clear at the top of the Rio Paralympic standings on Sunday.

The Asian nation has now won 39 gold medals, 16 more than second-placed Britain and 21 more than Ukraine, who are third.

Sunday's fourth day of competition saw China win four gold medals in swimming, three in athletics, two each in table tennis and powerlifting, and one apiece in shooting and archery.

Powerlifter Tan Yujiao was one of several Chinese athletes to set new world records as she clinched gold in the women's -67kg Group A.

Tan lifted 138.5kg with her final attempt to beat her own record of 138kg set in Hungary last year.

Kazakhstan's Raushan Koishibayeva took silver with 113kg and Egypt's Amal Mahmoud bronze with 108kg.

"I didn't really think of how all the others would perform or what they're doing," Tan told the Paralympic News Service. "I just focus on myself because I think this sport is where you compete against yourself, the only one I have to defeat is myself."

"The training is like a daily routine so it is really hard to keep going but I still take a shine to it and I have determination. That's how I come to this level and I'm happy about that."

Tan, who was born with one leg longer than the other, was a silver medallist at the London 2012 Games.

She said she had improved immeasurably over the past four years.

"I was 22 years old back then and I've learned a lot of different things since so it is not like the old times," she said.

"It really comes down to being more mature and having more determination. I think the most important thing was my passion for this sport."

Another to break a world record was Zhou Hongzhuan as she secured gold in the 400m T53.

The 27-year-old clocked 54.43 seconds to eclipse the previous benchmark of 54.69 set by Australia's Angela Ballard in June.

"I am very happy and excited to win this medal because I trained a lot but I did not expect to win," Zhou said.

It was Zhou's fourth Paralympic gold medal. In addition to Sunday's triumph, Zhou won the 400m T53 and 800m T53 in London four years ago, and the 800m T53 at the Beijing 2008 Games.

She also took silver in the women's 100m T53 on Thursday. Zhou's leg impairment is the result of polio.

Liu Benying also set a new world record as he grabbed gold in the 200m freestyle S2.

The 20-year-old clocked three minutes 41.54 seconds to beat the previous record held by countryman Zou Liankang by almost eight seconds.

Zou took silver in 3:42.58 and Ukraine's Serhii Palamarchuk claimed bronze in 3:43.69.

Liu's limb impairment is the result of an accident when he was eight.

And Yao Juan broke her own world record to win gold in the discus F44. The 32-year-old threw 44.53m with her first attempt to beat the record she set last year by more than a meter.

Fellow Chinese athlete Yang Yue grabbed silver with a personal best throw of 43.47m and Cuba's Noraivis de la Heras Chibas took bronze with 32.47m.

Yao has now won gold medals at four different editions of the Paralympic Games.

She won the shot put F42/44 title at the London 2012 Games and also triumphed in javelin at Sydney 2000 (F44) and Beijing 2008 (F42-46).

Yao, who suffers from impaired muscle power, took up para-athletics in 1998.

Liu Lei secured his third Paralympic gold medal by winning the powerlifting men's -72kg Group A.

The 28-year-old recorded a best lift of 221kg to defeat Rasool Mohsin of Iraq by just 1kg. Nigeria's Nnamdi Innocent grabbed bronze with a best effort of 210kg.

"I am extremely happy and it means a lot to me, even more than the previous two [gold medals]," Liu said.

"This one was really difficult for me because I've been fighting with a lot of injuries and I also had a problem with my heart. It was really difficult but I'm very happy to have won."

Liu also won gold in the -67.5kg at the London 2012 Games and in the -75kg at the Beijing 2008 Games.

His impairment is the result of polio, which he contracted as a child.

Teenager Li Junsheng beat local favorite Daniel Dias to claim gold in the 100m breaststroke SB4.

The 16-year-old touched the wall in 1 minute, 35.96 seconds, just 17 hundredths of a second ahead of the Brazilian. Colombia's Moises Fuentes Garcia clinched bronze in 1:37.40.

Dias said he was surprised by Li's performance but added that his rival was a deserving winner.

"I confess ... The Chinese surprised me, and all of us. China are also showing the world that they are very strong and we have to lift our game."

Li was diagnosed with cerebral palsy when he was one and took up swimming in 2012.

Chen Junfei leapt a personal best 4.77m to win gold in the women's long jump.

The 24-year-old recored a best jump of 4.77m to beat Australia's Taylor Doyle by 15cm. Poland's Anna Trener-Wierciak took bronze with 4.53m.

Chen also won gold in the 200m T38 at the London 2012 Games.

Wang Yinan grabbed his fourth Paralympic gold medal by winning the men's 100m freestyle S8.

The 26-year-old touched the wall in 56.80 seconds to beat his compatriot Song Maodang by 1.33 seconds. Britain's Craig Josef pocketed bronze in 58.19.

Wang also won the 100m freestyle S8, 400m freestyle S8 and 4x100m medley relay 34 points at the London 2012 Games.

He was born with cerebral palsy, which resulted in an impairment to his right foot.

Liu Jing beat South Korea's Seo Su-Yeon to win gold in the women's table tennis CL 1-2. Liu took the match 3-1 (11-6, 9-11, 12-10, 19-17) in 31 minutes at Riocentro.

It was the 28-year-old's fifth Paralympic gold medal after her singles and doubles triumphs at the London 2012 and Beijing 2008 Games.

Italy's Giada Rossi defeated Thailand's Chilchitparyak Bootwansirina 3-0 in the bronze medal match.

China defeated Iran 5-3 in the final to clinch gold in the mixed team recurve archery event. Italy beat Mongolia 5-1 in the bronze medal match.

Shooter Huang Xing won gold in the P3 mixed 25m pistol SH1 by defeating Sweden's Joackim Norberg.

Huang won the final 7-5 to claim his first Paralympic title at the Olympic Shooting Center. Lee Ju Hee took bronze after beating Australia's Christopher Pitt 7-3.

"It is my first Paralympic Games and first medal and I am very happy and very excited. I have completed my goal and achieved my dream come true," the 30-year-old told the Paralympic News Service.

"It's an honor to win for China. I was very nervous but I think I had a little bit of luck as well."

Huang's left arm was injured at age nine in an accident.

Lin Ping clinched her second Paralympic gold medal by winning the women's 200m individual medley SM9.

Lin touched the wall in two minutes 35.64 seconds, just 20 hundredths of a second ahead of Spain's Sarai Gascon. Britain's Amy Marren took bronze in 2:36.26.

Lin also won gold in the 50m freestyle S9 at the London 2012 Games.

"Never did I think I would win a medal here," the 22-year-old told the Paralympic News Service.

I just wanted to go fast and to pay back my coach. My coach and her husband have been training me for 10 years. We are like a family. For the last year we have had private training together, spending all our time together.

"She never pressured me, just helped me improve and encouraged me. I hope we are together all my life."

Lin lost her right hand in an accident at age four.

And Feng Panfeng won his third straight Paralympic table tennis singles class 3 title by defeating Germany's Thomas Schmidberger three sets to one.

The 26-year-old took the match 11-5, 7-11, 11-9, 11-8 in 27 minutes at Riocentro.

It was his fourth Paralympic gold medal, having won the same event at the Beijing 2008 and London 2012 Games in addition to the team class 3 title in London.

Feng's impairment is the result of the effects of polio.