Enoh Eyong's goal seven minutes from time saw the 'Indomitable Lions' escape with a draw after the Slovakians, who played a part in Czechoslovakia's rich World Cup history, had taken the lead through Kamil Kopunek in the sixth minute.
Kopunek scored with a great strike from 18 metres out after being set up by Chelsea midfielder Miroslav Stoch, giving no chance to Cameroon goalkeeper Hamidou Souleymanou.
The Slovaks dominated the first-half against a Cameroon side still without their superstar striker Samuel Eto'o, who has been given time off since winning last Saturday's Champions League title, and their defence whenever threatened held firm, superbly marshalled by Liverpool defender Martin Skrtel. The European side - who are in Group F at the finals in South Africa with defending champions Italy, New Zealand and Paraguay - could even have taken a 2-0 lead but Stanislav Sestak's shot rattled back off the crossbar.
Lions courting questions
Cameroon - who are in Group E for the 11 June - 11 July tournament along with Denmark, Japan and the Netherlands - came back into the match after that and finally were rewarded when Ajax midfielder Eyong struck.
Cameroon will be hoping that Eto'o doesn't opt to boycott the finals after he had warned on Friday he might not bother going after coming under heavy criticism from Roger Milla, their star from the 1990 edition when they only missed out on the semi-finals in a penalty shootout defeat by England.
This draw comes on the back of a 0-0 draw with non-qualifiers Georgia earlier in the week and they will be looking for a vastly-improved performance in their 1 June friendly with 2006 World Cup semi-finalists and fellow finalists Portugal in Covilha, Portugal. They have a final friendly after that against fellow qualifiers Serbia on 5 June in Belgrade.