By Gabriel Tan
The result, coupled with a 2-0 victory in Thursday's first leg at the Clementi Stadium, saw the Stags advance to the final 5-0 on aggregate, where they will next meet SAFFC, who saw off Gombak United in the other last-four encounter.
While two-goal hero Aleksandar Duric and Jamil Ali, who came off the bench to lay on assists for all his side's goals, received the plaudits after Sunday's game, Tay reserved praise for Dreven, a player he criticised just weeks ago for a shocking display in a 4-3 loss to Albirex Niigata in the Great Eastern-YEO's S.League.
"Overall, it was an exciting game and it would have been very different in they had scored in the first half," the Tampines boss said.
"Our goalkeeper made two fantastic saves to keep it at 0-0 and as a result, we came back in the second half stronger and managed to grab the win."
The Croatian custodian was especially brilliant midway through the first half, when he produced a stunning flying save to tip away a blistering drive by Phil Younghusband, before denying the Philippines international again shortly after with a smart reflex stop to keep out a fierce snapshot.
However, the Stags' evening was slightly soured by yellow cards to defender Anaz Hadee and midfield lynchpin Gligor Gligorov, who will both miss the final against the Warriors, and Tay admits the former will be particularly missed given he does not have many options at the back.
"Already our squad is very thin and now we'll have two players out for the final in Gligor and Anaz," he added.
"We only have three defenders and that's a big problem for us."
Still, the ex-Singapore international admitted reaching the final was the most important thing on the night, and is looking forward to what he hopes will be a thrilling encounter against a fellow giant in Singaporean football.
"Of course, it's good that we are in the final," Tay stressed. "I hope it will be an exciting game against SAFFC and that the fans will turn up and show their support.
"At the end of the day, the most important thing is to play exciting football, like in today's [Sunday's] game."
Tampines are looking to complete a domestic double and are also top of the table in the Great Eastern-YEO's S.League, although both DPMM FC and Albirex are refusing to let up in their chase for the title.