World No. 1 Roger Federer and defending champion David Nalbandian strode into the Masters Cup semi-finals on Thursday after matching straight-sets wins.
Federer won 7-6 (7/2), 6-4 to send Ivan Ljubicic crashing out, after Nalbandian ended Andy Roddick's hopes 6-2, 7-6 (7/4).
The results raise the possibility of a rematch of last year's classic final, when Nalbandian outlasted the Swiss in five sets.
"It would be quite interesting to see that again and hopefully it will end the other way round," Federer said. "It's still a bit of a surprise that Nalbandian came through like last year but I guess he deserved it because he beat Ljubicic and beat Roddick convincingly today."
The 2003 and 2004 champion was broken in the first game before recovering to win a first-set tie-break. He broke in the third game of the second set before sealing Ljubicic's fate with an ace.
The victory made Federer the first player in more than 20 years to win 90 matches in a season, after Ivan Lendl clocked up 106 in 1982.
It also maintained his 100 percent record in round-robin matches after five consecutive appearances at the season-ending tournament, and stretched his current winning streak to 27.
Ljubicic, who was knocked out at the same stage on debut last year, said he took advantage of Federer's patchy start but couldn't keep pace when the top-ranked Swiss hit his stride.
"My problem is we have a pretty similar game. Whenever I raise the level he raises the level too and I really can't catch him," he said.
All four Red Group players started Thursday's matches with the chance of qualifying or being eliminated.
Nalbandian's preparations were rocked by news that his cousin and godson Lautaro was crushed to death by a lift in the family's home city of Cordoba.
"It was terrible," he said. "I mean, I couldn't enjoy the match the way I would like to. Life is like this. I can do nothing from here. I tried to push as hard as I could on court."
Nalbandian started strongly, having the measure of Roddick's big serve and picking off his opponent in a series of baseline rallies.
The American looked sluggish on court and did not come to life until the second set, breaking Nalbandian to force the tie-breaker.
He led 3-1 before Nalbandian came back, taking the lead at 4-3 and winning when Roddick netted.
"I had very good shots in the beginning and it looked like Andy didn't really wake up until the second set," Nalbandian said. "That's why I took advantage fast. He didn't serve very well in the beginning and I returned, that's the key to why I got away very fast in the first set."
Roddick was relaxed about his elimination which came two nights after he came close to breaking a three-year losing streak against Federer.
"I think two nights ago was a little bit more emotionally taxing than tonight," he said. "It's always a little bit easier to look forward to a vacation than it is trying to qualify. What's done is done, now we'll look forward to next year."
The world's top eight players compete in the elite, US$4.45 million tournament.
The final Gold Group matches will be played today.