Two top men's tennis stars seek a berth in the quarterfinals of the U.S. Open on Monday. No. 3 seed Andy Murray faces No. 15 seed Kevin Anderson, while No. 2 seed Roger Federer faces American John Isner, who is seeded No. 13.

On the Labor Day holiday, Murray will take on Anderson at Louis Armstrong Stadium at about 2:30 p.m. ET, while Federer and Isner tangle at 9 p.m. ET at Arthur Ashe Stadium. Both matches will be televised on ESPN2. A live stream of the matches can be found on WatchESPN.

Federer has not surrendered a set in the tournament, and only Philipp Kohlschreiber was able to take four games off of him in a set. The Swiss star has reached the quarterfinals in 10 of the last 11 years. Isner, a native of North Carolina, has won all eight of the sets he's played, with Jiri Vesely retiring after two sets in a third-round matchup. The deepest Isner has gone in the U.S. Open was a quarterfinals appearance in 2011.

Murray, who earned his first Grand Slam by prevailing in New York in 2012, has had his troubles in the early rounds, receiving a test from the erratic Nick Kyrgios, and then needing five sets to hold off Adrian Mannarino in the second round. In the third round, the Scot had an easier time with a straight-sets win over Thomaz Bellucci. Anderson was able to escape past Andrey Rublev in the first round, and would go on to win his next two matches in straight sets. The South African, who at age 29 is playing some of his best tennis, has never reached the quarterfinals of a Grand Slam.

Last year's champion, Marin Cilic of Croatia, has already booked his spot in the quarters and will face Jo-Wilfried Tsonga of France. Also on Sunday, Spaniard Feliciano Lopez defeated Fabio Fognini to also reach the last eight. Fognini became a top story at Flushing Meadows after coming back from two sets down to upset 14-time Grand Slam champion Rafael Nadal.

Kei Nishikori, who reached the finals in 2014, has been the highest seed to falter at the U.S. Open, losing in a five-set opening-round match to Benoit Paire. Nishikori entered the tournament as the No. 4 seed.