The result means Zambia are regional champions for the fifth time, one less than gold medal leaders Zimbabwe, and lift the trophy for the first time since 2013 having lost out in the previous two finals.
For Botswana it is more heartache as their quest for a maiden COSAFA Cup glory continues following a second final defeat, the previous one coming in 2016 when they lost to South Africa.
Botswana had the better of the opening half, but could not make that dominance count on the scoreboard.
Midfielder Mothusi Cooper forced a good stop from Zambian goalkeeper Sebastian Mwange when his low shot from outside the box needed attention.
At the other end, star Zambian forward Lazarous Kambole was played on goal by Kaseba, but his lob over the head of Botswana gloveman Ezekiel Morake bounced just the wrong side of the post.
Zebras midfielder Thero Setsile then saw his shot from close-range blocked as the teams went into the break at 0-0, but with Botswana enjoying the lion’s share of the possession.
They had the first chance of the second period too when Segolame Boy’s free-kick from 25-yards beat the all, but not Mwange, who was able to make the save.
The breakthrough finally came on 78 minutes when Kaseba stooped to score with his head, the ball eluding Morake in the Botswana goal, a moment of huge celebration for Chipolopolo.
Kaseba should have made it 2-0 when the ball came his way shortly afterwards and, with more time than he realised, he swung a boot that pushed the ball onto the crossbar and over.
His goal sealed the win though and Zambia were able to celebrate COSAFA Cup success again.
Meanwhile, Gerald Phiri Jnr was named Player of the Tournament and claimed R20,000 in prize-money, while Zambian keeper Mwange was crowned Goalkeeper of the Tournament and took home the same amount.
The R20,000 for the Golden Boot will be shared between three players – the Malawian duo of Phiri Jnr and Mhango, and Mauritius striker Ashley Nazira – who all scored three goals.
Zambia win R500,000 for their first-place finish, while Botswana will take home R250,000 as runners-up. Zimbabwe take R150,000 for finishing third, Leostho have R125,000 for fourth, while Plate winners South Africa will get R100,000.
The next COSAFA tournaments are not far off and history will be made this year.
The COSAFA Women’s Championship will be staged in Port Elizabeth from July 31-August 11, while the COSAFA Under-20 Women’s Championship will run concurrently at the same venue from August 1-11.
Later in the year will also be a COSAFA Under-17 Women’s Championship in Mauritius (September 13-22) followed by a boys’ competition in the Under-17 age-group in Malawi (September 26-October 5).
The final competition will be the COSAFA Under-20 Championship for men in Zambia from December 4-15.
Botswana 0 Zambia 1 (Kaseba 78’)
Matches Played: 20
Goals scored: 48
Biggest victory: Malawi 3 Seychelles 0 (Group B, May 26)
Most goals in a game: 4 – Eswatini 2 Mauritius 2 (Group A, May 25); Eswatini 2 Comoros 2 (Group A, May 27); South Africa 2 Botswana 2 (Quarterfinals, June 2); Zambia 2 Malawi 2 (Quarterfinals, June 2); Lesotho 2 Zimbabwe 2 (Third-Place Play-Off, June 7)
3 goals – Gabadinho Mhango (Malawi), Ashley Nazira (Mauritius), Gerald Phiri Jnr (Malawi)
2 – Felix Badenhorst (Eswatini), Issaskar Gurirab (Namibia), Youssouf Ibroihim (Comoros), Richard Mbulu (Malawi), Luther Singh (South Africa)
1 – Tsoarelo Bereng (Lesotho), Khama Billiat (Zimbabwe),Segolame Boy (Botswana), Emmanuel Chabula (Zambia), Chikoti Chirwa (Malawi), Thatayaone Ditlhokwe (Botswana),Lebogang Ditsele (Botswana),Charles Hambira (Namibia),Soulaimana Ibouniyamine (Comoros), Jeituso (Mozambique), Hassan Kajoke (Malawi), Tapson Kasebe (Zambia), Ali Nassim (Comoros), Absalom Iimbondi (Namibia), Joslin Kamatuka (Namibia), Siboniso Mamba (Eswatini), Grant Margeman (South Africa), Leeroy Mavunga (Zimbawe), Joel Mogorosi (Botswana), Sera Motebang (Lesotho), Austin Muwowo (Zambia), Sabelo Ndzinisa (Eswatini), Boina Bacar Raidou (Comoros), Evans Rusike (Zimbabwe), Tafadzwa Rusike (Zimbabwe), Dan Serunkuma (Uganda), Jane Thaba-Ntso (Lesotho), Sadney Urikhob (Namibia), Witi (Mozambique)