The Black Caps are hoping to keep the heart rate monitors in the medical kit in today's third one day cricket match against South Africa.

Less than 10 runs has been the difference in the opening two matches, with the series locked at one-all heading into Wellington.

Black Caps paceman Tim Southee said that while it's great to be involved in games that go down to the wire, they're hoping for a more convincing win.

The Proteas, meanwhile, are putting emphasis on their batsmen ahead of the match. South African hitter JP Duminy says nobody's yet to assume full responsibility in the middle.

"When you get the opportunity, you make sure you take it on for the team," he said.

"Hopefully we can put in a better performance from a batting unit perspective."

First ball is scheduled for 2pm, with South Africa winning the toss and choosing to bat first.