Hafeez, who was also adjudged Player of the Match, said after the game that South Africa's 266/2 in 50 overs was below par even as Hashim Amla cracked a 100 and Rassie van der Dussen scored 93 on debut.
"It's a team effort," Hafeez said. "It was not a par score on this track, so we were confident chasing it. To be very honest, we were very sure as a team we should chase this one. The start given by Fakhar and Imam(-ul-Haq) was brilliant, Babar (Azam) gave us momentum."
A sparkling performance from Mohammad Hafeez, another half-century for the in-form Imam-ul-Haq, and a superb death-bowling performance all helped Pakistan claim the first ODI against South Africa, despite Hashim Amla's 27th ODI hundred.#SAvPAK REPORT 👇https://t.co/UsGzApnPZ4 pic.twitter.com/joGVC3P0wN— ICC (@ICC) January 20, 2019
Opener Imam-ul-Haq (86) and No.3 Azam (49) laid a platform for the likes of Hafeez to capitalise on, which they did successfully.
With this win, Pakistan maintained their unbeaten record at St. George's Park. They have now won three out of the four matches they have played at the venue, with one match ending without result.
Pakistan captain Sarfaraz Ahmed also credited his batsmen for their first win of the tour. "The batting was very responsible," Ahmed said. "In the middle overs, Shadab (Khan) was great, as well as Imad (Wasim). And the way our fast bowlers bowled was very good."
South Africa captain Faf du Plessis also felt that his team were short of where they should have been. "The two guys (Amla and van der Dussen) batted really well, but perhaps there were 10 or 15 runs that we could have pushed a little harder for," he said.
Shadab (1/41) and Hasan Ali (1/42) bowled well in the middle overs and did not allow the well-set South African batsmen to accelerate. "Pakistan bowled better than us over fifty overs today," du Plessis said.
"Pakistan batted really well [too], you have to give credit where it's due. Some great learnings for us, and we know where we can get better.
Ice-cool from The Professor!— ICC (@ICC) January 19, 2019
Mohammad Hafeez's 71* seals the first ODI against South Africa with five wickets and five balls in hand.
What a game!#SAvPAK LIVE 👇https://t.co/GPUFjyHgoB pic.twitter.com/YSG7XyGmtU
"An in-form Hashim Amla is great for us. Rassie played beautifully, he had intent right through his innings. We need to adapt. You're not going to always get conditions for the fast bowlers."
The second ODI of the five-match series will be played on Tuesday, 22 January at Kingsmead, Durban.