Following is a summary of current sports news briefs.

Kvitova reaches fourth round with win over Pegula

Czech Petra Kvitova struggled with unforced errors but still had enough weapons to defeat American Jessica Pegula 6-4 6-3 on Friday to advance to the fourth round of the U.S. Open. The two-times Wimbledon champion had 28 unforced errors and five double faults but moved up a gear when it mattered to win her first career meeting with baseline battler Pegula.

NFL notebook: Washington cuts RB Peterson

Adrian Peterson, the former NFL MVP and four-time All-Pro running back, was surprisingly released by the Washington Football Team on Friday. Head coach Ron Rivera said Peterson’s leadership was valued, especially after Derrius Guice was released amid off-field turmoil this summer. Rivera said that he tossed and turned overnight in pondering breaking the news to Peterson.

New father McIlroy says playing with more freedom is paying off

Rory McIlroy said playing without expectations following the birth of his first child had helped him rediscover some of his best form as he shot a six-under 64 in the opening round of the season-ending Tour Championship in Atlanta on Friday. The Northern Irishman, who began the day in 12th at three under, got his title defense off to a flying start just five days after his daughter Poppy was born and said that he was surprised by how quickly he found his groove.

Serena wary of Stephens threat in third round

Serena Williams continues her push for a record-equalling 24th Grand Slam trophy when she takes on Sloane Stephens on Saturday in an all-American clash of former U.S. Open champions. Williams has blitzed through the draw without dropping a set but faces a tricky third-round test against the 26th-seeded Stephens, whose run to the 2017 U.S. Open title propelled her to a career-high ranking of No. 3.

Djokovic brushes aside Struff to advance in New York

Top seed Novak Djokovic continued his dominance of Jan-Lennard Struff on Friday with a 6-3 6-3 6-1 win to advance to the fourth round of the U.S. Open. Djokovic, a three-times champion at Flushing Meadows, was never really pushed by the German, who has taken just one set off the Serb in their five career meetings.

Athletics: Farah breaks world record for one hour run

Britain’s Mo Farah broke the world record for a one-hour run by completing a distance of 21,330 metres at the Brussels Diamond League athletics meeting on Friday. The 37-year-old eclipsed the previous record of 21,285 metres set by Ethiopia’s Haile Gebrselassie 13 years ago.

WADA to look at new sanctions after U.S. threat to pull funding

The World Anti-Doping Agency (WADA) said on Friday it will consider amending rules to punish stakeholders who withdraw funding after the United States threatened to pull its contributions unless reforms it demands are met. The WADA executive board meets on Sept. 14-15 where the threat of a U.S. pull out will be on the agenda after some governments expressed concern over a country being able to refuse to meet its funding commitments without facing any significant consequences.

Athletics: Hassan breaks women’s one-hour record by 413 metres

Sifan Hassan, of the Netherlands, smashed the world record for the women’s one-hour race by more than a lap when she ran 18,930 metres during the Brussels Diamond League meeting on Friday. The Ethiopian-born athlete, who won gold in the 1500 and 10,000 metres at the world championships last year, ran 413 metres — more than one whole lap — further than the previous record of 18,517, set by Ethiopian Dire Tune in 2008.

Messi reluctantly staying at Barcelona after all

Lionel Messi ended speculation about his future at Barcelona by announcing on Friday that he would reluctantly stay for another season rather than tackle his career-long club in court. A week after saying he wanted to leave the Liga side, and with a contract row still raging, the 33-year-old six-time player of the year gave the news Barca fans were hoping for.

Osaka survives scare to reach last 16 in New York

Former champion Naomi Osaka survived a third-round scare before grinding out a 6-3 6-7(4) 6-2 victory over fearless Ukrainian teenager Marta Kostyuk to reach the last 16 of the U.S. Open on Friday. The Japanese fourth seed initially looked like she would enjoy a routine day on the court but was forced to dig deep to secure victory after two hours and 33 minutes against an 18-year-old making her U.S. Open main draw debut.