Cheetahs pip Connacht at the death
Two tries from wing Matt Healy and one from Eoin Griffin, combined with two penalties from the boot of Jack Carty, looked to have sealed Connacht's second win on the road.
But their efforts were not enough to see off the South Africans, who scored early through Uzair Cassiem and again in the second half through Sibhale Maxwane, with Marais kicking fourteen points for the win.
With the triumph, Cheetahs have closed the gap on Munster in second place in Conference A to just six points, whereas Connacht missed the opportunity to chase down Cardiff Blues in fourth.
Cassiem opened the scoring for the Cheetahs after just three minutes, picking and going on the blindside of a ruck five metres out to trot in untouched.
Niel Marais converted the try then added three more points to give the hosts a 10 point lead within 10 minutes.
Connacht responded through Healy, who was put in down the left after some fluid hands, and Jack Carty added the extras.
After Marais slotted another penalty, Healy then got his second in the same corner after the ball was spun out to him, but Carty couldn't convert to take the lead.
Marais knocked over yet another kick at goal after an explosive break from Craig Barry forced a penalty for Cheetahs, but Carty responded and converted an effort of his own just before half time.
The Irish flyhalf then took the opportunity to take the lead for the first time after the break, slotting his penalty to go 18-16 up.
He then made a slicing break after waves of pressure on the Cheetahs defence and off-loaded to Griffin who ran in under the posts.
The hosts' replied instantly with some great running, as Barry cut inside from his wing and passed to substitute Maxwane to cross the whitewash, with Marais adding the extras to close the gap to two points.
Connacht looked to have kept the Cheetahs out and were on track for just their second victory on the road, but the Cheetahs pushed on and were rewarded for their determination.
Clayton Blommetjies' monstrous kick to touch from a penalty meant the hosts had a line-out five metres out and managed to win a late penalty when Connacht failed to release on the floor.
Marais stepped up as the clock ticked towards 80 minutes and calmly slotted the ball between the posts to seal a dramatic victory at the death.
Tries: Cassiem, Maxwane
Cons: N Marais 2
Pens: Marais 4
Tries: Healy 2, Griffin
Cons: Carty 2
Pens: Carty 2
Cheetahs: 15 Clayton Blommetjies, 14 Craig Barry, 13 Francois Venter (captain), 12 Nico Lee, 11 Luther Obi, 10 Niel Marais, 9 Mthokozisi Mkhabela, 8 Uzair Cassiem, 7 Henco Venter, 6 Paul Schoeman, 5 Reniel Hugo, 4 Justin Basson, 3 Johan Coetzee, 2 Torsten van Jaarsveld, 1 Retshegofaditswe Nche.
Replacements: 16 Jacques du Toit, 17 Charles Marais, 18 Tom Botha, 19 Renier Bernardo, 20 Teboho Mohoje, 21 Tian Meyer, 22 Fred Zeilinga, 23 Sibhale Maxano.
Connacht: 15 Tiernan O’Halloran, 14 Cian Kelleher, 13 Eoin Griffin, 12 Pita Ahki, 11 Matt Healy, 10 Jack Carty, 9 Caolin Blade, 8 John Muldoon (captain), 7 Jarrad Butler, 6 Sean O’Brien, 5 James Cannon, 4 Ultan Dillane, 3 Finlay Bealham, 2 Tom McCartney, 1 Denis Buckley.
Replacements: 16 Shane Delahunt, 17 Denis Coulson, 18 Dominic Robertson McCoy, 19 Gavin Thornbury, 20 Eoghan Masterson, 21 James Mitchell, 22 Craig Ronaldson, 23 Niyi Adeolokun.
Referee: Stuart Berry (South Africa)
Assistant referees: Ben Crouse (South Africa), Jaco Kotze (South Africa)
TMO: Johan Greeff (South Africa)