Not using two opcodes, but here's a way without any comparison operators. assuming the stack looks like [a, b].
OP_SUB makes the stack [a-b]
If a < b then a-b < 0, which would mean the last byte must be have the significant bit enabled.
OP_SIZE OP_1SUB OP_SPLIT
will let us extract the last byte.
So the stack will look like [(a-b)[:-1], (a-b)[1:-1]]
then use, 0x01 0x80 OP_AND to see if the bit is set, then you must use OP_7 OP_RSHIFT because the bitcoin stack machine will consider negative