* Zambia lead but concede two late goals
* Tunisia move on to four points in Group B
By Mark Gleeson
EBIBEYIN, Equatorial Guinea, Jan 22 (Reuters) - Yassine Chikhaoui's glancing header three minutes from time secured Tunisia a 2-1 win over Zambia in their African Nations Cup Group B match at Estadio de Ebebiyin on Thursday.
It gives Tunisia four points and a strong chance to advance to the quarter-finals while Zambia, who were tournament winners in 2012, are in deep peril but have only themselves to blame after missing a host of chances.
Emmanuel Mayuka, who had two good first half opportunities, broke the deadlock on the hour with a rasping shot but will rue heading straight at Tunisia goalkeeper Aymen Mathlouthi in the 41st minute and then, on the stroke of halftime, miscuing a shot straight in front of goal.
Zambia dominated most of the first half exchanges and eventually got reward for their attacking application when Mayuka was found unmarked at the back post to fire home from close range. He was set up by a pass from captain Rainford Kalaba, who jinxed his way through a static Tunisian defence.
Mayuka later went off with a groin injury.
A missed effort from Evans Kangwa was further evidence of a wasteful night, allowing Tunisia to stay in connection.
Tunisia equalised from a 70th minute corner where Syam Ben Youssef touched the ball on for Ahmed Akaichi to score at the back post as Zambia's defence were caught ball-watching.
Youssef Msakni, restored to the starting line-up, then set up the winner with a chase of a long ball, which he kept in play before chipping in a cross that Chikhaoui connected after timing his run into the defence with perfect precision.
Both Tunisia and Zambia drew their opening game but Zambia must now win their last game against Cape Verde on Monday while a draw for Tunisia against the Democratic Republic of Congo, at the same time in Bata, should be enough to see them into the quarter-finals. (Editing by Justin Palmer; email@example.com; +240222770533; Reuters Messaging: firstname.lastname@example.org)