Big wins for holders Nigeria and South Africa mean Group B at the Women's Africa Cup of Nations will be decided by the final games on Saturday.

Nigeria got their title defence back on track with a 4-0 win over Zambia in the first fixture on Wednesday.

South Africa then thrashed former winners Equatorial Guinea 7-1.

Despite conceding 12 goals in two games, Equatorial Guinea still have a mathematical chance of making the semi-finals.

If they can beat Nigeria on Saturday and South Africa beat local rivals Zambia they will progress.

But South Africa know they need just a point from that game if they are to advance to the last four.

Nigeria's Super Falcons were under pressure having lost their opening Group B game 1-0 to South Africa on Sunday.

Those nerves were settled when Desire Oparanozie opened the scoring just before half-time.

Before that goal the Super Falcons had found it hard to break down a stubborn Zambian defence.

It was the boost Nigeria needed who started off the second half at a fast pace.

With Francisca Ordega, Rasheedat Ajibade and Amarachi Okoronkwo all scoring in the second half to give the defending champions the victory.

He margin of victory should have been more but the usually reliable Asisat Osoala, who as the tournament's top goal scorer two years ago failing to make the most of three one-on-one chances against Zambia's goalkeeper in the space of three minutes.

South Africa looked in control of their game against Equatorial Guinea when after 19 minutes Linda Motlhalo scored from the penalty spot and moments later Mpumi Nyandeni added a second.

Equatorial Guinea, who have twice been crowned African champions, pulled one back against the run of play just before half-time through Elena Nkuandum.

It proved to be false hope though as Banyana Banyana fired home five unanswered goals in the second half.

First to strike was Refiloe Jane before two from Christine Thembi Kgatlana in as many minutes Amanda Mthandi made it six with the rout completed by Jermaine Seoposenwe.

The results mean that mathematically all four teams have a chance of reaching the last four or being knocked on Saturday.

The top three at the tournament all clinch places at the World Cup in France next year, although Equatorial Guinea are not eligible for one of those places following a Fifa ban on them for using ineligible players in qualifying for the 2016 Rio Olympics.