Wimbledon 2015: Defending champs off to attacking start

It was business as usual for the top seeds on the opening day of Wimbledon 2015. Defending champion Novak Djokovic registered a 6-4 6-4 6-4 win over Philipp Kohlschreiber of Germany. (Source: AP)

Djokovic, who beat Roger Federer in last year's final, was happy to be back at Centre Court and was rarely troubled during the match. (Source: Reuters)

If the defending champion powered on, one former champion bowed out on Day 1. 2002 winner Lleyton Hewitt saved three match points before falling in five sets to Finland's Jarkko Nieminen. Hewitt had announced that he will retire after next year's Australian Open. (Source: Reuters)

Former and defending champs apart, French Open champ Stan Wawrinka looked sharp in his opener. The Swiss registered a comfortable win and can well face Djokovic, his French Open final opponent, in the semifinal. (Source: Reuters)

Wawrinka, playing on Centre Court, beat Joao Sousa of Portugal 6-2 7-5 7-5 (3). (Source: Reuters)

Kei Nishikori was stretched to five sets by Simone Bolelli before the fifth seed registered a 6-3 6-7 (4) 6-2 3-6 6-3 win. (Source: Reuters)

In the women's singles contest, there weren't any casualties. Maria Sharapova blew away Johanna Konta 6-2 6-2 to advance. (Source: AP)

Having returned to the United States to rest and recover from a virus that contributed to her fourth-round defeat by Czech Lucie Safarova at the French Open, Sharapova looked revitalised as she triumphed in the sunshine of Centre Court. (Source: Reuters)

The Williams sisters were at the their dominating best as they romped into the second round after winning their respective matches. Serena beat 113th-ranked Margarita Gasparyan of Russia 6-4, 6-1 to extend her Grand Slam winning streak to 22 matches. (Source: AP)

The 16th-seeded Venus recorded a double-bagel, beating Madison Brengle 6-0, 6-0 in just over 40 minutes. (Source: AP)