Hertha Berlin forward Kalou came off the bench to enlighten Sunday's drab friendly in Abu Dhabi with an 84th-minute winner.
Played in front of a sparse crowd at Sheikh Zayed Sports City, the match between the Ivory Coast - the bookmakers' favourites to win this year's AFCON - and reigning champions Nigeria, who failed to qualify for the 2015 edition, was bereft of any real quality.
But Kalou made sure Herve Renard's side got their preparations under way with a win, as he finished well from Cheick Tiote's cut-back.
Nigeria's Rabiu Ali carelessly gave the ball away to Tiote, and the Newcastle United midfielder squared for Kalou after a strong drive forward.
The Ivory Coast face Sweden in Abu Dhabi on Thursday before beginning their AFCON campaign against Guinea on January 20.
In Sunday's other AFCON warm-up match, Liassine Cadamuro had a mixed day as Algeria drew 1-1 with Tunisia.
Osasuna defender Cadamuro - who was cut from Christian Gourcuff's provisional 26-man squad before being handed a reprieve when Essaid Belkalem withdrew due to injury - headed his side into the lead in the 38th minute in Rades.
However, the 26-year-old was sent off just three minutes later, and Tunisia took immediate advantage by equalising through Wahbi Khazri's stunning free-kick before half-time.
Algeria begin their AFCON challenge against South Africa on January 19, while Tunisia start their campaign against Cape Verde Islands 24 hours earlier.
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