Group D winners Ivory Coast rescued a 2-2 draw against Algeria on Wednesday to maintain their Africa Cup of Nations unbeaten run.
All four goals at Rustenburg's Royal Bafokeng Stadium came in a 16-minute spell in the second half with Algeria taking the lead in the 64th minute with substitute Sofiane Feghouli scoring two minutes after coming on for Ryad Boudebouz, who missed a penalty in the first half.
They doubled their lead six minutes later when Hilal Soudani fired in a header after escaping his marker and meeting a long perfect cross from Feghouli wide on the right.
The Ivorians, who had already qualified for the knock out stages, struck back in the 77th minute when Drogba outjumped the defence to head home.
They equalised three minutes after that when a powerful shot from Wilfried Bony took a huge deflection off Algerian defender Djamel Mesbah.
Ivory Coast had a chance to snatch the win at the end but Drogba was off balance and overstretching as he tried to poke the ball in.
The Elephants face Nigeria in the last eight on Sunday.