Brumbies coach Jake White admitted that his team were lucky to keep their Super Rugby title hopes alive after they edged the Cheetahs 15-13 in Canberra.
The Cheetahs scored a late try and flyhalf Riaan Smit had the unenviable job of kicking the conversion which would have sent the game into extra time.
"We got lucky with that kick at the end there, but when I look back at that game from last week when we didn't play well there's no doubt that our graph has started to go up," Head Coach Jake White said.
"We spoke a lot about the fact that finals footy means playing for 80 minutes and we had to play 81 to get the result. "
"It doesn't get any bigger than a sell out semi-final at Loftus, it's massive for this group of players.
"They're a South African side and we know what they're like," said White.
"They'll play with their forwards and use Morne Steyn to add the extras. But if we play to our best there's no reason we can't take a result."
The Brumbies have already played the Bulls this season that match was in Canberra and the Brumbies won 23-20 in March.
The Bulls lost to the Stormers in their last regular Super Rugby season match to the Stormers but before that they enjoyed a nine match winning streak which started the week after they had lost to the Brumbies.
The Brumbies left Canberra for Sydney on Sunday night and will fly to South Africa on Monday where they will meet the Bulls in the Semi-final with a place in the grand final at stake.
The Bulls are unbeaten at home in 2013.