Delray Beach, FL (SportsNetwork.com) - Top-seeded Kevin Anderson was an easy first-round winner at the Delray Beach Open tennis event Tuesday.

American John Isner was not as fortunate.

Anderson dominated John-Patrick Smith, 6-3, 6-3, while the second-seeded Isner fell victim to Marinko Matosevic in a 6-4, 6-4 final on the hardcourts at Delray Beach Tennis Center.

Another American, sixth-seeded Sam Querrey, exited with back issues after taking the first set from Alejandro Gonzalez, who advanced to take on Donald Young. Young, one of four Americans who advanced to the second round, got the better of Ivan Dodig, 7-5, 7-5.

Seventh-seeded Steve Johnson and Tim Smyczek were the other U.S. natives moving on Tuesday. Johnson's opponent, Mikhail Kukushkin, retired in the second set due to an illness.

Fifth-seeded Adrian Mannarino and eighth-seeded Viktor Troicki also won their matches Tuesday, as did Bernard Tomic, Yoshihito Nishioka, Thanasi Kokkinakis, Andrey Rublev and Yen-Hsun Lu.

Three teenagers -- Rublev (17), Kokkinakis (18) and Nishioka (19) -- reached the second round for the first time in tournament history.

Anderson won this event in 2012 and was last year's runner-up to U.S. Open titlist Marin Cilic.

The 2015 Delray champion will earn $84,250.