A former World No.1 stands in the way of a former World No.1 reaching the final where another former World No.1 will be waiting - it is what the BlackRock Tour of Champions is all about.

Pete Sampras and Thomas Muster both topped the ATP rankings in the 1990’s, and they will face each other in the final round-robin match at the BlackRock Tour of Champions event in Sao Paulo, Brazil on Saturday. If Sampras wins, a mouth-watering final clash with Marcelo Rios (pictured) surely awaits.

Pete Sampras explains why he wants to be courtside when Roger Federer breaks his Grand Slam record.

Boths Sampras and Rios have won their two group matches to-date, with Sampras serving and volleying his way past Marc-Kevin Goellner for a 6-3, 6-4 victory on Friday, and Rios crushing Jaime Oncins 6-2, 6-1.

"I was happy with my level of play today,” said Sampras.

“I definitely felt a bit more comfortable out there, serving and volleying a bit more than yesterday. I also feel more adapted to the court. I have a tough match tomorrow against Muster that I will be looking to win to reach the final on Sunday."

The American won nine of his eleven meetings against Muster during their careers, and will head into their round-robin clash as the favourite. Muster has been struggling this week. He lost 6-3, 6-3 to Brazil’s Fernando Meligeni on Friday, and said:

“I was not hitting the ball well. I think it has to do with the altitude of Sao Paulo. But Fernando played a great match and deserved to win.”

Rios, meanwhile, was in irresistable form, and now needs to defeat Jaime Yzaga to reach the final.

“I’m getting used to the court and I believe I played better than yesterday. I just hope I can play like this tomorrow and advance to the final,” he said.