Cape Town - The fifth and final ODI match against Sri Lanka in Centurion on Friday could see the Proteas regain their No 1 position in the ICC ODI team rankings.
This comes after current leaders Australia lost their three-match series 2-0 against New Zealand.
A whitewash against Sri Lanka will see the Proteas leapfrog Australia and head to New Zealand - and possibly England for the Champions Trophy - as the No 1-ranked ODI side.
"Five-nil is important in order to get to No 1," Faf du Plessis told the media after South Africa's 40-run victory at Newlands on Tuesday.
"For a while we've been targeting to get back to the top in all formats and we're getting there very quickly.
"Five-nil will be a great achievement - no matter who you will play against. A lot of the teams will take the foot off the gas, but we're been really good throughout this series."
Despite this series being a one-sided affair, Du Plessis says they've learnt to become more consistent and not let their opponent get ahead at any moment.
"You have to beat who is in front of you, I think that's something we've done really well," said Du Plessis.
"We're been consistent throughout the series, we haven't taken our foot off the gas.
"Our batsmen have been disciplined and from a bowling point of view - yes, Sri Lanka is not the best batting line-up to bowl to - but we're still doing what's required."
At Newlands on Tuesday, the Proteas bowling attack was under pressure for the first time this ODI series, which saw a flurry of runs and a solid opening partnership of 139 between Niroshan Dickwella and skipper Upul Tharanga.
Wayne Parnell took 4/58, as the Proteas bowlers dug deep to wrap up their 13th consecutive home win.
"Today (Tuesday) was a pressured situation, we know they score runs on top and the bowlers didn't start off well, but they came back," said Du Plessis.
"It's important that as a bowling unit we get pushed, especially a young bowling unit, that's the difference between winning a tournament and not - is the pressure.
"It will be nice to challenge the bowlers, but if the situation isn't coming then you've done something really well."
The final ODI against Sri Lanka gets underway on Friday, February 10 at 13:30.
The Proteas then travel to New Zealand on Saturday and will play their first T20I game against the Black Caps on Friday, February 17.