Shimlas and Pukke will contest the 2015 Varsity Cup final after securing semi-final wins over UCT and Tuks on Monday.
Pukke, the 2014 runners-up, claimed a dramatic 29-28 victory over the table-topping Tuks, after Johnny Welthagen scored a try in the 77th minute.
Both sides scored tries in the space of two minutes early on in the match, before Pukke snuck into the lead courtesy of the boot of fullback Rhyno Smith, who slotted a conversion and penalty.
The hosts responded with another unconverted score through John Jackson to level things up, but as their flyhalf kept on dragging his attempts wide, Smith turned his kicking opportunities into points, with a second penalty before converting captain Jeandré Rudolph's try for a 19-10 lead at the break.
Tuks launched a strong second-half comeback, when outside centre Dan Kriel ran the length of the field to score against the run of play to cut Pukke's lead to a point.
Both sides managed to breach the opposition's defence once again, bringing the score to 24-23 in favour of the visitors.
Tuks then took the lead when they ran the ball from inside their half, using the width of the field. Eighthman Clyde Davids drew two defenders, then threw a pop pass to fullback Riaan Britz, who sprinted down the right flank for what they thought was the winning try.
But there was one more twist to come. Welthagen, who attempted the infamous drop goal in last year's final against UCT when time was up, dummied and stepped his way around the Tuks defence before brushing off the last tackler to send Pukke into their second successive final.
Earlier in the day, Shimlas, who remain unbeaten, booked their first ever Varsity Cup final with a comfortable 21-10 win over UCT in Bloemfontein, despite having a try disallowed.
Ikeys kept the pace in the first half, as both teams scored twice. Shimlas, however, converted their tries and led 16-10 at the break. The second half was less action-packed, as Shimlas defended their slender lead before left wing Maphutha Dolo's try sealed the match.
In Varsity Shield action, UWC and Wits played to a 21-21 draw in Bellville, their second this season, a result which ended UWC's title hopes and afforded Wits a final berth. Elsewhere, UKZN thrashed Fort Hare 42-0, to confirm their status as 2015 Varsity Shield finalists ahead of UWC.
Shimlas (21) – Tries: Niell Jordaan, Daniel Maartens, Maphutha Dolo. Conversions: Niel Marais (2).
UCT (10) – Tries: Jason Klaasen, Chad Solomon.
Tuks (28) – Tries: Wiaan Liebenberg, John Jackson, Dan Kriel, Clyde Davids, Riaan Britz. Conversion: Joshua Stander.
Pukke (29) – Tries: Marno Redelinghuys, Juandré Williams, Jeandre Rodolph, Johnny Welthagen. Conversions: Rhyno Smith. Penalties: Smith (3).
UWC (21) – Tries: Quaid Langeveldt, Gordon-Wayne Plaatjies, Chadwin Robertson. Conversions: Darian Hock, Langeveldt.
Wits (21) – Tries: Angus Gordan, Joshua Jarvis, Rhyno Herbst. Conversions: Brandan Hewitt (2).
UKZN (42) – Tries: Marais Louw (3), Retief Marais, Langelihle Shange, Adam Wessels. Conversions: Siphatisene Dube (4)
Photo: Catherine Kotze/SASPA