Rafael Nadal closed in on Roger Federer at the top of the world rankings after the second-seeded Spaniard moved past Nicolas Lapentti 7-6 (7-3) 6-1 in the quarter-finals of the Western & Southern Financial Group Masters on Friday.
Nadal has won his last five tournaments and if the 22-year manages to claim the championship at this hardcourt event, he will overtake Roger Federer as the number one player in the world.
The top-ranked player for a record 235 weeks, Federer had the opportunity to keep Nadal at bay a bit longer had he reached the semi-finals here, but a third-round loss to Ivo Karlovic on Thursday ended that possibility.
By reaching the semi-finals, Nadal will become No.1 on August 18 and he is guaranteed to move atop the rankings on August 11 by finishing as the runner-up.
Nadal, who is an ATP-best 64-7 this season and is riding a 32-match win streak, connected on 67 percent of his first serves and saved all three break points. He had two break opportunities and capitalised on both.
The unseeded 31-year-old from Ecuador had made a habit of knocking out seeded Spaniards this week, with consecutive upsets of No. 5 David Ferrer and No. 10 Fernando Verdasco en route to the quarters.
Another interesting side story was that Lapentti had beaten Nadal in their only previous meeting. While that match took place five years ago in Bastad, it was on clay - a surface Nadal has dominated throughout his career.
Nadal will meet third-seeded Novak Djokovic in a semi-final clash. Djokovic downed Latvia's Ernests Gulbis 6-3 6-4, in the quarters.
"I thought that I was serving much better, and day after day I'm getting stronger in the segment of my game, which is really important coming up to the final stages of the tournament," said Djokovic, who improved to 43-10 on the season, 22-5 on hard courts.
Djokovic won his first Grand Slam title earlier this year at the Australian Open and appeared destined to challenge Federer and Nadal atop the rankings, but his season has taken a downturn after a disappointing second-round exit at Wimbledon and a quarter-final loss to Andy Murray in Toronto last week.
The 21-year-old Serb is likely excited about facing Nadal on a hard court. A win would exact a small measure of revenge for Djokovic, who twice failed to beat Nadal on clay this spring with the number two ranking hanging in the balance.
On the opposite side of the draw, Karlovic built on his win over Federer when he upended unseeded German Philipp Kohlschreiber 7-6 (8-6) 7-6 (7-3) in a quarter-final.
"Well, I mean, of course in a tiebreak it's most important to serve well and to use your chances," Karlovic said. "I was playing well actually this week, so I'm happy about that."
"It was important because I felt like I can win, that I have my chances, but I was trying not to put pressure on myself after yesterday's win."
The hard-serving Croat - who leads the ATP with 657 aces this year - came into this tournament on a three-match losing streak, but has regained the form that led him to a title at Nottingham earlier this year.
Karlovic will face the eighth-seeded Murray, who overcame a slow start to post a 2-6 6-2 6-1 win over veteran Spaniard Carlos Moya, the 2002 champion.
Murray looked uninspired in losing