India's Sania Mirza made a winning start in the women's doubles as she and her American partner Bethanie Mattek-Sands defeated Russia's Alla Kudryavtseva and American Sloane Stephens 6-4, 6-2.
Serena Williams, the 2002, 2003, 2009 and 2010 champion, reached the second round with a 6-2, 6-4 win over Barbora Zahlavova Strycova of the Czech Republic.
Defending champion Petra Kvitova reached the second round with a 6-4, 6-4 win over Akgul Amanmuradova of Uzbekistan, but only after surviving an early struggle.
Mardy Fish made a winning return to tennis. In his first match following a procedure to address a frightening heart scare, the world number 12 beat Spain's Ruben Ramirez-Hidalgo 7-6 (7/3), 7-5 7-6 (7/1) and looked comfortable moving around the court.
Japan's Kei Nishikori earned his first ever win at Wimbledon as the 19th seed marked his return from injury with a 7-5, 6-3, 6-4 victory over Mikhail Kukushkin of Kazakhstan.
Lleyton Hewitt's 10th anniversary party of his 2002 Wimbledon title was gatecrashed by French fifth seed Jo-Wilfried Tsonga who cruised to a 6-3, 6-4, 6-4 win.