By ESPNSTAR.com staff
Heading into the tie at the Thunder Castle Stadium leading 3-2 from the first leg, Buriram netted what proved to be the only goal of the game in the 77th minute when Adisak Kraisorn skipped past a challenge inside the area and clinically fired into the bottom corner.
And any hopes of a late comeback by the Glass Rabbits were firmly extinguished in the 86th minute when they were reduced to ten men after Valery Hiek received his marching orders.
Buriram will now meet Thai Division 1 League side Ratchaburi, who played out a 2-2 draw at TOT, in a heated encounter that saw five players sent off, to advance 3-2 on aggregate.
Wednesday's Thai League Cup Semi-final 2nd Leg Results
Buriram United 1-0 Bangkok Glass (4-2 on agg.)
TOT 2-2 Ratchaburi (2-3 on agg.)