The Lions beat the Sharks 27-10 at King's Park on Saturday to secure top place in the Super Rugby standings and secure home advantage if they reach next month's final.
They will now play the Sharks again, but at home at Ellis Park in next Saturday's quarter-final and by virtue of top place in the overall log at the end of 17 weeks of the group phase are guaranteed to play at home if they advance further to the semi-finals and final.
The Lions, runners-up in last year's competition, outscored the Sharks by three tries to one after a slow start with Springboks Malcolm Marx and Andries Coetzee going over to ensure a 13-10 halftime lead and captain Jaco Kriel adding one in the second half.
"It's an amazing feeling to be top of the log. We've taken it week by week," Kriel said.
Lions fly half Elton Jantjies slotted four penalties but made the error that led to the Sharks' only try when his 25m drop out was short and went straight into the hands of Sharks wing Kobus van Wyk, who had the pace to beat a surprised Lions defence for an easy score.
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Sharks fly half Garth April opened the scoring with a 10th minute penalty and also added a conversion.
Defeat for the Durban team proved fortuitous as it meant they avoided a lengthy trip to New Zealand to face the Crusaders, who now host the Highlanders instead in a South Island derby in the last eight.
The Lions finished ahead of the Crusaders, who lost their unbeaten record away against the Hurricanes in Wellington on Saturday to allow the Lions to leapfrog them and finish two points ahead. Both sides won 14 of their 15 group games.
