Zambia took advantage of some shambolic Senegal defending to claim a surprise win over the Group A favourites in the African Nations Cup.

Amara Traore's much-fancied side were all at sea in the first period as Emmanuel Mayuka gave Chipolopolo the lead after 12 minutes and Rainford Kalaba made it 2-0 eight minutes later.

Senegal were rejuvenated by a trio of substitutions after the break and it was one of the new men, Dame N'Doye, who pulled one back in the 74th minute, but they could not find an equaliser.

Senegal will still hope to advance from the group, in which Equatorial Guinea beat Libya 1-0 in the tournament's opening fixture earlier in the day, but they will have to improve on some dreadful defending which allowed Zambia to take the initiative from the first minute.

Kalaba created trouble down the left for Senegal early on and turned the ball low into the box, but Mayuka could not get a telling touch and Senegal defender Souleymane Diawara intervened.

It merely delayed the blow for Senegal, though, as Nathan Sinkala's free-kick was headed back across goal and Mayuka, one of two unmarked players in the centre, was on hand to head home with ease.

Senegal threatened to get back into the game when Moussa Sow's near-post header from Mamadou Niang's inswinging free-kick was saved at his near post by Kennedy Mweene.

But Mayuka was through again as Senegal persisted in playing a high line. Senegal goalkeeper Bouna Coundoul came out to meet him and the ball eventually broke to Isaac Chansa, whose shot was blocked by Diawara.

Still Senegal did not heed the warning and they paid again when Kalaba ran into acres of space, his run found by Christopher Katongo, and finished low past Coundoul.

Mayuka threatened again four minutes before the break, but his strike from distance was pushed wide by Coundoul at his near post.

Senegal went close after 52 minutes when half-time substitute Issiar Dia did well down the right, cut the ball back for Sow and he lifted his angled shot just over the bar.

It was a similar story after 64 minutes when Kader Mangane headed the ball across goal and Demba Ba's snapshot went narrowly wide.

And Ba went even close three minutes later.

Papiss Demba Cisse, only on the pitch for a few seconds after replacing Sow, showed great skill down the right to flick the ball up and beat Sinkala before somehow getting a cross in for his new Newcastle team-mate, who thumped a header against the bar.

It was another substitute, N'Doye, who finally got the goal, controlling a long pass from Guirane N'Daw on his chest before hammering the ball low past Mweene at his near post, but Senegal were oddly subdued thereafter.