The good news for Zambia is that Herve Renard remains unbeaten while wearing white at the Cup of Nations. The bad news is that the champions began their defence of the Cup of Nations with a draw against Ethiopia and that it took all the luck Herve's costume could muster even to get away with that – despite the Walya Antelopes having to play the last hour with 10 men.

Last week, Renard insisted that the squad was "better than last year at the same stage. But look what happened then: we had nothing to show for ourselves and we won the tournament." He has been keen to praise their discipline – "in one year, there has been no problem. Not a player showing up late for a training camp, no behaviour problem" – which again represents a contrast to last year when the midfielder Clifford Mulenga was sent home for failing to apologise after breaking a curfew. Disappointing friendly results, Renard said, could be explained by the desire to give as many players as possible a game, and even then his side had played well without capitalising on their chances.

There was an element of that against Ethiopia – Zambia had 18 shots off target, more shots than any side managed in any game at the last Cup of Nations – and on a better, less bobbly pitch, they may have been able to take advantage of their superiority. Renard, to his credit, didn't use the abysmal surface – difficult weather conditions haven't helped, but the uneven pitch is surely related to the white elephant nature of the stadium, which doesn't host football on a regular basis – as an excuse, perhaps because he knew that the high bounce had saved his side in the first half and that, until Ethiopia had their goalkeeper, Jemal Tassew, sent off, Ethiopia had looked by far the more threatening side.

Last year, Zambia thrived by sitting deep, absorbing pressure, and getting the ball forward to Emmanuel Mayuka to hold it up for the thoughtful skills of Christopher Katongo and the forward charges of Rainford Kalaba down the left. That their strategy was based on rapid transitions rather than patient passing was made clear by the fact they had the lowest pass completion rate of any side on the tournament. That made them ideally suited to playing against teams who expected to beat them – as Ghana in the semi-final and Ivory Coast in the final clearly did – but is less well suited when the onus is on Zambia to attack. Renard had hinted at his concerns on that score, noting that "there's no place for champions to hide".

The result was a back line that, without the protection of two deep-lying central midfielders, seemed uncertain how high a line to play. The partnership of Hichani Himoonde and Stopila Sunzu in central defence, so solid a year ago, became a liability. It was after they both ignored a long ball from Adane Girma that Saladin Seid found himself alone on the edge of the box with just Kennedy Mweene to beat. Showing fine awareness, he lobbed the ball over the keeper, only for it to take a crazy bounce and loop over the bar.

That was Ethiopia's first great chance; their second came six minutes later as Saladin Seid's penalty was saved low to his left by Mweene, justifying once again his reputation as a penalty specialist. It would be wrong to suggest Ethiopia were in total control at that point, for Jemal made a fine reaction save from Katongo, but they were definitely on top and looking the more dangerous. Everything changed, though, just after the half-hour as Jemal came charging out in an attempt to intercept a long through-ball, arrived long after Chisamba Lungu had nudged the ball past him, and crunched his studs into the Zambian's hip.

Ethiopia's manager, Sewnet Bishaw, tried to defend his goalkeeper, and there were lengthy protests as Jemal received treatment and was carried off on a stretcher but red cards don't come much redder. With the extra man, Zambia took the lead shortly before half-time, Collins Mbesuma – replacing Mayuka in the only change from the side that started last year's final – seizing on Isaac Chansa's knock-down and finishing calmly.

At that stage and for much of the second half there seemed only one winner but as the second goal didn't come, Renard lost patience. Off came the left-back Joseph Musonda – the player he had carried on to the pitch to join the celebrations at the end of last year's final – and on went the forward Jacob Mulenga. That meant Lungu switching to left-back and it was he who was caught out of position as Himoonde's mistake allowed Seid to lay in Adane Girma. Renard's desire to find a second goal was understandable but his switch seemed out of keeping with the pragmatism he had shown last year: was he, perhaps, feeling the pressure of being champions, the need to make a statement?

Although Renard said his side got exactly what they deserved, Zambia created enough chances to think they were a little unfortunate only to draw – although whether they would have done had it not been for Jemal's red card is doubtful. Nigeria's draw against Burkina Faso further limited the damage. There is pressure now on Zambia's game against the Super Eagles, who were dourly unimpressive in their opener, but the fact that they will not be expected to take the game to their opponents should help Zambia. They had a bad day and got away with it; the key now is to take advantage and the best way to do that is probably to return to the functionality of a year ago.