The 31-year-old double Olympic and triple world champion over the distance gave birth to her first child last August and has vowed to get back into the medal mix.
"I'm so excited, that is so good," said the Jamaican. "I took the time off, I didn't pay any attention to what others said about my comeback.
"I continued to work hard and London is definitely the best place and to come here and win, with my first sub-11, is fantastic," added the Jamaican, who won her second Olympic gold and a 200m silver at the stadium in 2012.
"I'm used to sacrificing and making sure that my path is right. Being a mother is my first priority and to come back and be flexible with my training is wonderful and I'm so excited about next year now."
American Dezerea Bryant took second in 11.04 ahead of Jamaica's Jonielle Smith, who ran an 11.07 personal best.
Season leader Marie-Josee Ta Lou, her Ivory Coast team mate Murielle Ahoure and Jamaican Elaine Thompson all opted to run the 100m in the Monaco Diamond League on Friday night.
- Countries: Jamaica