Madrid, Spain (SportsNetwork.com) - Two-time defending and four-time overall champion Rafael Nadal was an easy second-round winner Wednesday at the Madrid Open.

After enjoying an opening-round bye, the third-seeded former world No. 1 great eased past American two-time NCAA singles champion Steve Johnson 6-4, 6-3 at the Magic Box in this clay-court Masters 1000 event.

Nadal captured a second straight Madrid title last year by beating Japan's Kei Nishikori in the final.

Up next for the nine-time French Open king will be Simone Bolelli, who overcame fellow Italian Luca Vanni 4-6, 6-3, 6-2 on Day 4.

In other action involving Top-10 seeds, No. 6 Czech Tomas Berdych topped last week's Estoril champion Richard Gasquet of France 7-6 (7-3), 7-5; No. 7 David Ferrer took care of fellow Spaniard Albert Ramos-Vinolas 6-4, 6-0; Spain's Fernando Verdasco ousted No. 9 U.S. Open champ Marin Cilic of Croatia 6-7 (5-7), 7-6 (7-5), 6-3; and No. 10 Bulgarian Grigor Dimitrov came from behind to defeat Italian Fabio Fognini 3-6, 6-2, 7-5.

Also on Wednesday, Argentine Leonardo Mayer erased 11th-seeded Spaniard Feliciano Lopez 7-6 (7-3), 7-6 (8-6); 12th-seeded Frenchman Jo-Wilfried Tsonga outlasted game American Jack Sock 6-3, 1-6, 7-6 (7-4); 14th-seeded Spaniard Roberto Bautista Agut dismissed American Sam Querrey 7-5, 6-4; and 16th-seeded American John Isner held off Brazilian Thomaz Bellucci 7-6 (7-5), 6-7 (11-13), 6-1.