It's South Africa's last dance at the end of two months away from home and they will want to end on a high. They've already won the T20I series, albeit that their batting, in particular, has not been as convincing as they may have liked it to be and their combination remains uncertain. After this series, they will only have three matches against Sri Lanka to pin down a strategy for the T20 World Cup.
Ireland also have limited opportunity to firm up their game plan. Their series against Zimbabwe, which was due to start on August 11 will be rescheduled to later in August and September after changes in the regulations over who can enter Northern Ireland.
But Ireland have other reasons to put in a big performance in the finale. This is only their third T20I against South Africa and although the results show that they have lost both previous matches convincingly, the margin of the defeat in the second T20I belies how much pressure they were able to exert on South Africa. The Irish attack had South Africa 58 for 5 at the halfway stage of their innings and were in control of the first quarter of the match. They will want to be able to be in control for longer periods of time to pull off an upset.
(last five completed matches, most recent first)
South Africa WWWLW
In the spotlight
Temba Bavuma has had a lean run on this winter tour, with a top score of 46 in the second T20I in the West Indies and 103 runs in nine innings across ODIs and T20s. Form aside, Bavuma has looked comfortable in the leadership role and has handled his bowlers and field placements relatively well, he has presented a measured and even reflective image in his media engagements but will want to sign off with runs as South Africa head into a break before their major tournament assignment.
is three wickets away from entering the top 10 Irish wicket-takers' list in T20Is
and is likely to be used in a bowling capacity more frequently as the team prepare for the T20 World Cup. Stirling has bowled in the format 11 times, taken five wickets and has an economy rate of 5.62, compared with an economy of 7.54 overall, so the signs are there that Ireland are using him well. They'll want a little more from his batting, after no scores above 30 in the three ODIs and two T20Is so far.
It may be too early for Ireland to consider benching Kevin O'Brien - who has earned a duck in each of his last three internationals - but their patience with his lack of runs could be wearing thin. Mark Adair had a promising outing in the second T20I and will likely be retained.
Ireland: (possible) 1 Paul Stirling, 2 Kevin O'Brien, 3 Andy Balbirnie (capt), 4 Harry Tector, 5 George Dockrell, 6 Lorcan Tucker (wk), 7 Shane Getkate, 8 Simi Singh, 9 Mark Adair, 10 Josh Little, 11 Craig Young
South Africa may want to reconsider the composition of their batting line-up, which includes four openers in the top four, move Rassie van der Dussen up and include one of Kyle Verreynne or Heinrich Klaasen in the XI. They may also bring in the spin-bowling allrounder George Linde and one of Kagiso Rabada or Anrich Nortje for a last hurrah of this tour.
South Africa (possible): 1 Quinton de Kock (wk), 2 Temba Bavuma (capt), 3 Janneman Malan, 4 Aiden Markram 5 Rassie van der Dussen, 6 David Miller, 7 Wiaan Mulder, 8 Bjorn Fortuin/George Linde 9 Beuran Hendricks, 10 Kagiso Rabada/Anrich Nortje/Lungi Ngidi 11 Tabraiz Shamsi
Pitch and conditions
The home captain Andy Balbirnie judged the surface as a little slower than Ireland expected but acknowledged that it holds runs for those willing to apply themselves. Temperatures in Belfast are starting to cool off with Saturday's high forecast at 23 degrees and no rain until next week.
Stats and trivia
Tabraiz Shamsi is six wickets ahead of his nearest rival, Obed McCoy, in T20Is in 2021.
"Stirling gives us a different option up top. He is someone who probably hasn't bowled as much for Ireland as maybe he wanted to. We are going to try a couple of things in the coming weeks, with the World T20 in mind."
Ireland are fine-tuning bowling plans ahead of the T20 World Cup,, according to captain Andy Balbirnie.
"We are very fortunate to have someone like Shamsi in our team so we can bowl around him, make his life easier. We have the bowling unit to compete. It's a matter of game plans and clarity. On a day when the game plans are clear, it's an unstoppable unit."
Lungi Ngidi lauds Tabraiz Shamsi, the top-ranked T20I bowler in the world
Firdose Moonda is ESPNcricinfo's South Africa correspondent