Goals from debutant Relebohile Mofokeng (60') and Jayden Adams (64') secured the result, to move South Africa to top of Group C with 10 points.
Benin, who Bafana play next on Tuesday, are second with eight following their 2-2 draw with Zimbabwe on Thursday.
Speaking after the match, Broos told SABC: "It was very important today that we got the three points.
"We knew it would be a tough game and we played a team that didn't want to lose.
"We had four good chances in the first half and didn't score. We corrected some things and started the second half very well [and] immediately put them under pressure. Once the first goal went in we had done the most difficult bit.
“It (the first goal) was a bit late but most important is the victory and the three points.”