The Lions took full advantage of going up against a weakened Leinster outfit at Ellis Park on Sunday, While the Bulls and Stormers both suffered defeats in the URC.
The Irish outfit, who last week booked their place in the Champions Cup semi-finals after eliminating holders La Rochelle, had won 11 of their last 12 matches in the URC.
But, having made 13 changes, Leo Cullen’s side were blown away inside the opening 15 minutes as three Lions tries put them on the way to a victory which boosted their play-off hopes.
Leinster are now just one point clear of Glasgow with four rounds remaining while the Lions climbed into the top eight.
The Lions made a stunning start and grabbed the opening try inside 40 seconds as Richard Kriel and JC Pretorius combined to send Morne van den Berg in under the posts, with Sanele Nohamba converting before kicking a penalty seven minutes later.
A fantastic team try saw the Lions score again in the 10th minute, Francke Horn, Van den Berg and Marius Louw were all involved before the latter cruised over but Nohamba was unable to add the extras.
It went from bad to worse for Leinster three minutes later as Nohamba pounced on a loose ball before putting Quan Horn through, which the former converted for a 22-0 lead.
Leinster pair Liam Turner and Cormac Foley had tries disallowed for a knock on and forward pass respectively either side of the break before Nohamba’s penalty extended the Lions’ lead.
The Irish side finally got on the board in the 53rd minute when Ciaran Frawley pounced on a grubber kick from Harry Byrne, who added the extras.
But moments later the Lions secured the bonus point when Emmanuel Tshituka went over after loose play from Leinster but Nohamba could not convert.
Frawley claimed his second try following some slick passing from Leinster but Byrne missed his kick to leave the score 30-12.
Tshituka and Francke Horn added further tries in the final five minutes, both converted by Jordan Hendrikse, to cap an excellent day for the Lions.
The Ospreys clinched a a 27-21 victory against the DHL Stormers in Cape Town on Saturday, showcasing their play-off potential in the United Rugby Championship.
And they did it in bonus-point fashion, with wing Luke Morgan scoring two tries, while hooker Sam Parry and flanker Harri Deaves also touched down.
Jack Walsh kicked two conversions and a penalty, keeping the Ospreys firmly in play-off contention after comfortably the most impressive performance by a Welsh region this season.
Munster posted a statement victory in their quest for back-to-back United Rugby Championship (URC) titles as they beat the Bulls 27-22 at Loftus Versfeld.
Scrum-half Conor Murray’s try six minutes from time secured a bonus-point victory in Pretoria and took Munster above the Bulls into third place.
The home team had fly-half Johan Goosen sent off after 54 minutes for a dangerous challenge and Munster kept their composure to claim an outstanding win.
