Misbah-ul-Haq's men bounced back from an embarrassing defeat to minnows Zimbabwe last month to beat the Proteas by seven wickets in the first game of their two-Test series.
Former Test spinner Iqbal Qasim said the victory, achieved inside four days, should cheer up Pakistan's passionate but long-suffering fans.
"No doubt Pakistan needed this win," Qasim told AFP. "What happened in Zimbabwe left a bad taste in the mouth and everyone wanted Pakistan to lift its performance."
Pakistan restricted South Africa to 249 in the first innings with Mohammad Irfan and debutant spinner Zulfiqar Babar taking three wickets apiece before hundreds from Misbah and opener Khurram Manzoor took them to a 193-run lead.
Off-spinner Saeed Ajmal worked his magic on a dry pitch to snare 4-74 and leave the batsmen chasing just 40 for victory, which they managed after an early wobble saw three wickets go down.
South Africa's pace quartet blew away Pakistan's batsmen as they trounced them 3-0 in a Test series earlier this year.
Qasim said Misbah must be prepared for a tough response when the second Test starts in Dubai on October 23.
"I am sure the players will keep their feet on the ground as South Africa is the best team in the world and they will hit back strongly in the next match," said 50-Test veteran Qasim, who completed his tenure as chief selector in July this year.
Former captain Rashid Latif said the win was down to the shrewdness of Misbah, often criticised in Pakistan for his conservative approach to batting and captaincy.
"Credit goes to Misbah, he took a bold decision of dropping (Abdur) Rehman and Rahat Ali who both got wickets in Zimbabwe purely because of conditions and brought in the new opener Shan Masood," said Latif.
Pakistan have struggled to find the right combination at the top of the order but debutant Masood hit a composed first innings of 75 in a 135-run partnership with Manzoor -- the team's first century opening stand in more than 18 months.
Former batsman Basit Ali backed Misbah to prove his detractors wrong and seal the series in Dubai.
"Despite being criticised right, left and centre by armchair critics, Misbah has proved that he is the man to lead Pakistan," said Ali.