Yeah they can, will probably take them 3 to 4 attempts though. GenG only team to beat g2 on their first try (not counting teams from stage 1 and kickoff)
Also today was an off day for sentinels with the tech pauses stopping any momentum they had in the first game, and with sacy having personal issues which probably affected the whole teams mood. But I do think G2 looked really good, especially icy, if G2 keep icy in this form then I think it will be very close.