But they had no answer for Wesley who scored both inside and out, with 22 first half points on 10/13 shooting, giving the Saints a 44-43 point lead.
In the third quarter, Canterbury point guard McKenzie Moore scored seven straight points to give his side a slight two-point lead with four minutes to go.
Wellington replied with a 10-0 run to put them up 10 with twenty seconds left in the quarter. Moore answered with a three-point play to end third trailing by seven.
The Saints upped their defensive intensity in the fourth quarter to outscore the Rams 29-15. Shea Ili was the next best scorer with 18 points, and also added five assists and three steals.
Despite only scoring 12 points, Webster tallied nine assists and four steals.
The win means Wellington will be heading to their 17th grand final and will attempt go for their 10th championship.
Kendle ended the game with 25 points, Moore registered 21 points, nine rebounds and six assists for Rams who suffered their second straight semifinal defeat.
In the second semi, the Sharks arguably had one of their finest games of the season, executing on both ends of the court, thrashing the James Blond Supercity Rangers 106-67.
Judd Flavell had the luxury of rotating his squad and rest key starters as they led 85-41 at the end of the third. Alex Pledger was dominant inside with 24 points and 12 rebounds, and Reuben Te Rangi had 19 points against his former team.
Mitch McCarron scored a team-high 14 points, but the only other notable scorer was Earnest Ross Jr with 10.
The Rangers got off to a promising start leading 5-0, but it would be all Southland from there on, winning the opening quarter 31-20 and widening their lead to 24 at halftime.
There was no stopping Southland in the second half, extending their lead to 46 points.
The Sharks will make their third grand final appearance after winning the previous two.
The final tips off at ASB Arena at 5pm.
Results:
Wellington Saints 94 (Tai Wesley 36, Shea Ili 18, Corey Webster 12)
Canterbury Rams 73 (Jeremy Kendle 25, McKenzie Moore 21, Marcel Jones 10)
SIT Zerofees Sharks 106 (Alex Pledger 24, Reuben Te Rangi 19, Hayden Allen 13)
James Blond Supercity Rangers 67 (Mitch McCarron 14, Earnest Ross Jr 10)