Novak Djokovic won his 15th straight match and Roger Federer avenged last week's loss to Juan Martin del Potro, setting up a semifinal match between the two at the Paris Masters.
Djokovic beat Stanislas Wawrinka of Switzerland 6-1, 6-4, while Federer defeated Del Potro 6-3, 4-6, 6-3 Friday.
Djokovic, who saved all six break points, won 13 of 19 points at the net.
"Coming to the net is one of the improvements that I had recently," Djokovic said. "It didn't click so fast, trust me. I had to work and put in many, many hours on the practice court that you guys don't see."
Wawrinka lost five-setters against Djokovic at the Australian Open and the U.S. Open this year.
"When he plays that good it's very difficult, especially on this surface where he's the best, I believe," Wawrinka said.
Federer lost to Del Potro in last weekend's Swiss Indoors final, but the 17-time Grand Slam champion played nearly flawless tennis in the first set, making 17 winners and only four unforced errors.
Del Potro fought back in the second set, saving a break point in the opening game before converting his second break chance at 5-4 to level the match when fifth-seeded Swiss netted a forehand.
In the deciding set, Del Potro netted a forehand to drop serve at 3-3 and Federer won the match when the Argentine hit a forehand long.