Updated

Spanish crowd favorite Nicolas Almagro and Canadian slugger Milos Raonic were a pair of first-round winners Monday at the $4.425 million Madrid Open.

The 11th-seeded Almagro was leading Tobias Kamke 6-4 after one set when the German qualifier retired, while the 12th-seeded Raonic topped former world No. 3 Nikolay Davydenko of Russia 7-5, 7-6 (7-5) at this clay-court Masters 1000 French Open tune-up.

Raonic was not satisfied with his victory on Monday.

"I've just got to clean up crucial mistakes, take care of my serve, create a couple of opportunities on his serve and make the most of them," Raonic said after beating Davydenko.

Meanwhile, 14th-seeded Japanese Kei Nishikori whipped veteran Austrian left- hander Jurgen Melzer 6-3, 6-2, towering American John Isner dismissed Spanish qualifier Guillermo Garcia-Lopez 7-5, 7-6 (10-8) and rising 6-foot-8 star Jerzy Janowicz of Poland erased 6-foot-6 American Sam Querrey 6-3, 6-4 on Day 2 at The Magic Box.

In other opening-round play, German Florian Mayer defeated Aussie lucky loser Marinko Matosevic 6-2, 6-7 (3-7), 6-4; South African Kevin Anderson leveled Canadian qualifier Jesse Levine 6-2, 6-2; Uzbekistan's Denis Istomin drubbed Belgian qualifier Xavier Malisse 6-3, 6-2; Dutch qualifier Robin Haase got past Ukrainian Alexandr Dolgopolov 6-3, 6-7 (6-8), 6-2; Daniel Gimeno-Traver overcame fellow Spaniard Feliciano Lopez 2-6, 6-4, 6-2 and Bulgarian Grigor Dimitrov handled Spaniard Javier Marti 6-2, 6-4.

Dimitrov will next take on top-seeded and 2011 titlist Novak Djokovic in the second round, while Mayer is rewarded with a second-round match against 2008 Madrid champion Andy Murray.

The "Big Four" of Djokovic, Roger Federer, Murray and two-time winner Rafael Nadal are all on hand this week. The three-time Madrid winner Federer beat Czech slugger Tomas Berdych in last year's finale.