Tournament debutants Cape Verde looked to have the better of the more fancied Black Stars for much of the game, and in particular the first half. Ghana, however, were able to weather a storm of Cape Verde attacks to keep the sides level.
Cape Verde looked confident on the ball and attacked as a team, while Ghana were nervous and lacking in creativity.
Ghana's lack of initiative mattered little when the game-changing moment came in the 52nd minute when a penalty was awarded to the four-time Afcon champions. Mubarak stepped up and converted to make it 1-0.
Mubarak doubled his tally in second half injury time, when he caught Cape Verde on the break as they threw everyone forward.
He ran from the halfway line and slotted into an open goal to secure the 2-0 victory and vault his team into the last four.
Earlier, the first shot of the encounter fell to Elvis Macedo of Cape Verde in the seventh minute. Macedo found space on the edge of the area, and with time to spare could only deposit his shot into the stands.
Two minutes later, Christian Atsu for Ghana made a run down the right and his cross into the box could not find his man, with the Cape Verde defence rushing back to cover.
The first good chance fell to Cape Verde just under the quarter hour mark. After a number of passes in the box, Heldon Ramos for Cape Verde had acres of space and time, but made a mess of his shot which flew way over goal.
In the 17th minute, a foul in a dangerous area gifted Ghana a free kick on the right hand side 30-metres out. Kwadwo Asamoah went for goal from the setpiece, but directed his shot just past the far post.
Five minutes later, Ramos made a run from the right touchline infield towards the box. With teammates waiting in the area Ramos decided to have a dip at goal, but his shot was wildly misdirected.
Made no mistake
A 26th-minute corner by Atsu for Ghana was swung in fiercely, but the danger was cleared by some hurried Cape Verde defence.
Six minutes after the break Ghana were awarded a penalty.
Carlos Tavares was adjudged to have brought down Asamoah Gyan in the box and the referee pointed to the spot and yellow-carded Tavares for his efforts. Mubarak who had just come on made no mistake as he made it 1-0 to Ghana in the 54th minute.
Mubarak had also scored against Mali from a penalty in the group stages.
The goal opened up the game, and Cape Verde were on the attack from the restart with Abdul Fatawu Dauda in the Ghana goal producing some sharp saves.
A Macedo free kick from 25 metres out required a punch-block from Dauda in the 68th minute.
A number of probing Macedo free kicks followed, but despite exposing the Ghana defence his efforts could not find a Cape Verde player.
Mubarak found himself in space running onto a ball in the 85th minute leaving just Josimar Dias in the Cape Verde goal to beat, but his shot was rushed and sailed into the crowd.
Later Mubarak would score his second as Cape Verde sent all their players into the Ghana box and were caught on the break. – Sapa.