Africa Cup of Nations outsiders Zimbabwe kept a third consecutive clean sheet in warm-up matches by drawing 0-0 with title contenders Nigeria in rain-lashed Asaba on Saturday.
Zimbabwe, who will be in Group A with hosts Egypt, the Democratic Republic of Congo and Uganda, beat Comoros 2-0 last Saturday and drew 0-0 with Zambia three days ago.
Not conceding a goal in 270 minutes will encourage coach Sunday Chidzambwa and his team before they face Mohamed Salah-inspired Egypt in the Cup of Nations opener on June 21 in Cairo.
Nigeria, who will meet Guinea, Burundi and Madagascar in Group B, dominated possession in challenging conditions at the Stephen Keshi Stadium.
But a Super Eagles attack that included Alex Iwobi of Arsenal could not find a way past giant Zimbabwe goalkeeper George Chigova.
Iwobi did come close to ending the stalemate late in the second half with a shot from outside the box that flew just above the crossbar.
In northern Portugal, Angola scored twice within a minute midway through the second half via Ladislau and Mabululu to beat Guinea-Bissau 2-0 in another warm-up match.
Angola are in Group E at the Cup of Nations with Tunisia, Mali and Mauritania while Guinea-Bissau will face defending champions Cameroon, Ghana and Benin in Group F.