Madrid, Spain (SportsNetwork.com) - No. 5 seed Milos Raonic and former Australian Open champion Stan Wawrinka were a pair of second-round winners at the Madrid Open.

The Canadian slugger Raonic subdued Argentine Juan Monaco 6-3, 6-4 in 68 minutes, while Tuesday's nightcap saw the eighth-seeded Swiss Wawrinka best Portuguese lucky-loser Joao Sousa 7-6 (7-1), 7-5 at the Magic Box in this clay-court Masters 1000 event.

Some seeded stars played opening-round matches on Day 3, as No. 10 Bulgarian Grigor Dimitrov grounded American Donald Young 6-4, 3-0, retired; No. 12 Frenchman Jo-Wilfried Tsonga handled Czech Lukas Rosol 7-5, 6-3; No. 13 Frenchman Gael Monfils whipped Serb Viktor Troicki 6-2, 6-0; and No. 14 Spaniard Roberto Bautista Agut took care of Romanian wild card Marius Copil 7-5, 6-3.

In opening-round play, German Philipp Kohlschreiber clipped Colombian qualifier Alejandro Falla 6-1, 6-4 to set-up a rematch of Monday's championship match in Munich, where the German lost to Andy Murray at the BMW Open.

Also in the first round on Tuesday, Frenchman Richard Gasquet bested towering Croat Ivo Karlovic 6-3, 6-4; Argentine Leonardo Mayer leveled Luxembourg's Gilles Muller 6-3, 6-3; Spanish qualifier Albert Ramos-Vinolas overcame last week's Istanbul runner-up Pablo Cuevas of Uruguay 3-6, 6-3, 6-4; Fernando Verdasco fought back to beat fellow Spaniard Guillermo Garcia-Lopez 4-6, 6-2, 6-3; Spanish wild card Marcel Granollers got past Slovak Martin Klizan 5-2, retired; Aussie Nick Kyrgios dismissed Spanish qualifier Daniel Gimeno-Traver 6-2, 6-3; and American Jack Sock surprised Spanish wild card and recent Barcelona runner-up Pablo Andujar 6-4, 7-5.

The top seed for this French Open tune-up is Roger Federer, who enters the tournament after winning the inaugural Istanbul Open on Sunday. The 17-time Grand Slam champion won the Madrid title in 2009 and 2012, beating Rafael Nadal each time. He also won in 2006 when the tournament was played in the fall on hardcourts, and last played at the Magic Box in 2013, falling to Kei Nishikori in the round of 16.

Last week's Istanbul titlist Federer's second-round opponent on Wednesday will be the rising star Kyrgios.

Nadal is also entered this week and is the third seed. He is the two-time defending champion and a four-time Madrid winner, beating Nishikori in last year's finale.

The former top-ranked ace Nadal will face American Steve Johnson on Wednesday.

The aforementioned Murray, fresh off his first-ever clay-court title in Munich, is the other former winner in the draw. Seeded second this week, he won the 2008 Madrid title on a hardcourt.

On the practice courts, Murray could be seen getting acclimated to the ball's bounce in Madrid's altitude and warm, dry conditions, this following some cold and damp conditions in Munich.