Despite the victory, the Capetonians dropped from second to fourth on the log, tied with Munster and the Cell C Sharks on 56 points, but they are still in contention for a home quarter-final and possibly a home semi-final.
The first half was a tight affair as both teams tried to stamp their authority but were unable to cross the try-line – although the DHL Stormers came close in the opening seconds – which resulted in Leinster entering the break 6-3 up thanks to two penalty goals by flyhalf Ciarán Frawley to only one by the hosts’ Manie Libbok.
The Capetonians will rue a number of missed opportunities in the second half, but despite this they managed to score tries by Warrick Gelant (fullback) and Seabelo Senatla (wing) to add to a penalty try, while the visitors were only able to score one, by prop Ed Byrne.
The DHL Stormers came out with a bang with Ruhan Nel (centre) dashing over the try-line in the 34th second after a great break by Gelant, but flank Deon Fourie was pinned for obstruction, denying them a valuable try.
The Capetonians still had the first say with Libbok slotting a penalty goal in 15th minute, but this was cancelled out by back-to-back three pointers by his opposite number Frawley, which handed the visitors a 6-3 lead, and they managed to hold on going into halftime after stealing two invaluable lineouts – one of which was five metres from their try-line.
Leinster were dealt a massive blow three minutes into the second half as John McKee (hooker) received a yellow card after a string of repeated infringements, and the hosts capitalised on it with Gelant dotting down in style after sustained pressure close to the try-line to hand them the lead.
The DHL Stormers had three fantastic opportunities to score tries in quick succession soon after, but Senatla, Hacjivah Dayimani (flank) and Gelant were denied due to unforced errors.
Senatla, however, finally broke through in the 53rd minute, dotting down inches from the sideline as the home side continued to launch one attacking spell after the other.
Leinster struck back strongly with a well-worked try by Byrne following some good forward pressure on the stroke of the fourth quarter and the successful conversion levelled the scores at 13-13.
The DHL Stormers continued pile on the pressure close to try-line after Leinster found themselves skating on thin ice due to their ill-discipline, and the hosts reaped the rewards as they were awarded a penalty try in the 65th minute, while Leinster lost another player, scrumhalf Cormac Foley, to a yellow card in the process.
With neither team able to add to score in the closing minutes of the match, the DHL Stormers sealed the 20-13 win in a fantastic weekend of action for the SA sides.
DHL Stormers 20 (3) – Tries: Warrick Gelant, Seabelo Senatla, Penalty Try. Penalty goal: Manie Libbok.
Leinster 13 (6) – Try: Ed Byrne. Conversion: Harry Byrne. Penalty goals: Ciarán Frawley (2).