The 20-year-old Jessop could only celebrate his victory after crossing the line following a tight sprint win over Stuart Marais, but Haw was able to savour the win for the final few kilometres after she finally managed to get away from runner up, junior Tiffany Keep.
The tough course prepared by Rio Olympic course designer Nick Floros came into play almost from the start for both the men's and women's race with the lead group forming quickly and it was soon apparent who the contenders were.
In the men's race Jessop, Marais, Andrew Hill and Tyronne White formed the lead group but Jessop and Marais managed to get a small gap after the first section of singletrack. The two cross country specialists then used their explosive power on the short, steep hills sections to edge away from the marathon specialists.
As the approached the finish of the 42km race they had built a four-minute gap and were left to fight for the win. Marais almost made the decisive break with about five kilometres to go.
The biggest gap between us was about ten metres when Stuart had a small gap with about five kilometres to go," said an elated Jessop after crossing the line.
He attacked hard and had a gap of about ten metres; he went a bit animal like on me. It was a brutal attack and I almost popped, but just managed to claw my way back onto his wheel.
It was important for me to have a good race today as I prepare for the World Championships in two weeks time. It was a cross country type track so it was great preparation for the Worlds.
You only really know how well your training has gone through a result of some sort. I have been training hard so the main win for me today was that I was able to push myself, but the result was also important for my mindset. After this, I am now positive and so it is an extra boost before I leave."
I was one up from last year when I was third," said a disappointed Marais after the event. "I have finished third twice now and second is better than third at least, but hopefully I can get a win next year."
In the women's race, the initial climb also allowed Haw and Keep to use their cross country power to get away from the steady speed of Jeannie Dreyer.
It was really tough and the first climb was pretty steep and our legs were cold," said Haw after receiving the trophy, a replica of the Mandela Capture Site artwork. "Tiff and I worked together well and then about ten kilometres out we saw Jeannie coming back so I had to go and I managed to get away from Tiffany.
With the Worlds coming up this was my last hard week and now my tapering starts. This race was a good confidence booster before I get to the world's - hopefully my legs recover," she added with her trademark smile.
It was really cool to be a part of the Mandela Day events â€¦ and to get the big Mandela Day Trophies - the trophies are so smart."
In the 21km event, Scelo Mhlongo was a clear winner when he beat Daniel van der Watt by just over two minutes with Nkululeko Pewa third, a further three minutes back.
The women's race was a big win for Chloe Bateson who was 11 minutes ahead of Kelly Simkiss, who, as the girlfriend of the 42km winner, added to the joy in the Jessop camp after the event.
MEC for Cooperative Governance and Traditional Affairs Nomusa Dube-Ncube, on behalf of the provincial government, congratulated the race winners.
"Congratulations to Julian Jessop and Bianca Haw on winning the Mandela Day Marathon MTB Dash. They can be proud of beating a strong field to claim the titles for 2017."
1 Julian Jessop 1:42:11
2 Stuart Marais 1:42:14
3 Andrew Hill 1:46:38
4 Tyronne White 1:46:38
5 Henry Liebenberg 1:48:24
6 Leeroy Emslie 1:51:13
7 Marc Adam 1:51:21
8 Warren Price 1:51:38
9 Mazwi Smimango 1:52:21
10 Jedson Tooms 1:52:51
1 Bianca haw 2:04:03
2 Tiffany Keep 2:05:37
3 Jeannie Bomford 2:06:20
4 Natalie Bergstrom 2:06:41
5 Christie-Leigh Hearder 2:12:10
1 Scelo Mhlongo 50:50
2 Daniel van der Watt 52:37
3 Nkululeko Pewa 55:11
4 Jordan Bold 57:10
5 Bongumenzi Majola 58:12
1 Chloe Bateson 59:02
2 Kelly Simkiss 1:10:03
3 Judy Gous 1:13:16
4 Jodi Mackinnon 1:14:17
5 Rose Smith 1:16:21