Time for Nigeria to threaten in what has been an end-to-end start.

Victor Osimhen tries to reach Alex Iwobi's cross inside the penalty area and Ademola Lookman tries unsuccessfully to create trouble with a cross following a corner.

Angola scramble clear.

Gilberto sends an effort wide from the resulting corner.

Relief for Nigeria.

Best chance so far!

Gilberto heads the Angola corner on and Mabululu almost steers the ball in with his instep, only to be denied by Stanley Nwabali at his near post.

The Super Eagles keeper tips the ball away and it goes behind for a corner.

Angola - as they have throughout this tournament - mean business.

Now Angola have a promising spell, winning a corner on the right as part of a move featurng a darting Gilberto run.

Nigeria immediately threaten but can't get a clean shot away inside the Angola penalty area.

The underdogs survive an early scare with some frantic defending.

Nigeria launch the action! One of these sides will finish this evening in the Afcon 2023 semi-finals.

In tonight’s later quarter-final, two-time champions DR Congo face Guinea, who are making their first quarter-final appearance since 2015.

You can watch that match on BBC Three, iPlayer and on the BBC Sport website from 19:50 GMT.

Don’t miss it.

Image source, Getty Images

The anthems are ringing out in stirring fashion. Nigeria went first, and now Angola's players and fans are singing.

Image source, Getty Images

"They will be coming out to prove a point and we respect every country," Nigeria defender Kenneth Omeruo said of Angola.

"The idea now is to stick to our game and take it very seriously."

Want the full lowdown on the quarter-finals?

Read our guide to a final eight comprising none of the teams who reached this stage at the 2021 tournament.

Image source, Reuters

Nigeria are unchanged from the side which beat Cameroon in the last 16, with goalkeeper Stanley Nwabali shaking off the knee injury which saw him stretchered off in the closing stages on Saturday.

Nigeria XI: Nwabali, Ajayi, Troost-Ekong (capt), Bassey, Aina, Onyeka, Iwobi, Sanusi, Simon, Lookman, Osimhen.

Subs: Uzoho (GK), Ojo (GK), Omeruo, Awaziem, Yusuf, Aribo, Osayi-Samuel, Chukwueze, Musa, Iheanacho, Onuachu, Moffi.

Angola make one enforced change as Antonio Dominique replaces the suspended Neblu in goal.

Angola XI: Dominique, Eddie, Gaspar, Buatu, Carneiro, Fredy (capt), Show, Estrela, Gilberto, Dala, Mabululu.

Subs: Kadu (GK), Gelson (GK), Miguel, Keliano, Kinito, Paz, Bela, Milson, Luvumbo, Zine.

Image source, Getty Images

In a tournament characterised by surprise results and a level of entertainment that has occasionally been absurdly dramatic, the first game of the 2023 Africa Cup of Nations quarter-finals will also be the greatest shock of this round if the underdogs win.

Nigeria’s Fifa ranking of 42nd makes the Super Eagles the highest-ranked side left in the competition following the exits of Morocco (13th), reigning champions Senegal (20th)and Egypt (33rd) in the last 16.

Angola, their opponents in the last eight, are the lowest-ranked nation still in the competition at 117th in the world.

The Palancas Negras are unbeaten after drawing with 2019 winners Algeria in their opener before beating Mauritania, Burkina Faso and, in their largest win so far, Namibia 3-0 in the last 16.

Delson Gala is the second-top scorer in the competition, on four goals, while fellow forward Mabululu is one behind on three goals.

Nigeria produced their most convincing performance so far in their first knockout match, beating Cameroon 2-0 through two Ademola Lookman goals, having drawn with Equatorial Guinea and won 1-0 against Ivory Coast and Guinea-Bissau in the group stage.

Will the 2013 champions avoid another upset or are their opponents heading for a debut in the semi-finals? Stay with us for all of the action.