Liverpool striker Sadio Mane tapped in the opener from close range in the ninth minute from Lazio forward Keita Balde Diao's low cross.
Henri Saivet, who is on loan at St Etienne from Newcastle, then struck home a brilliant 20 yard free-kick four minutes later. Sadio Mane also had a lob cleared off the line by Costa Nhamoinesu.
Stoke city's Mame Biram Diouf should have increased Senegal's advantage, but blazed his left-foot shot over the crossbar.
Khama Billiat wasted a good chance for Zimbabwe just before half-time when he fired tamely at Abdoulaye Diallo. The keeper also produced a good block to keep out Nyasha Mushekwi's drive.
The Lions of Teranga have a maximum six points from two games in Group B. Tunisia are second with three points and both Algeria and Zimbabwe have a point each.
Watch and download match goals and highlights Senegal vs Zimbabwe 2-0 #afcon 2017 below