Mason, OH -- (Sports Network) - Rafael Nadal continued to inch his way closer to Roger Federer's No. 1 ranking, and each ranked player advanced to the semifinals at the $2.615 million Western & Southern Financial Group Masters tennis event.

It's only a matter of time before Nadal claims the No. 1 spot. If the Spaniard wins the title, he will become No. 1 on Monday. If Nadal loses in the final, he will become No. 1 on August 11. However unlikely, if Nadal loses in the semis, he will be No. 1 on August 18. The reigning four-time U.S. Open champion Federer has held the No. 1 ranking since February 2004.

Second seeded Nadal survived a first set scare to defeat Nicolas Lapentti of Ecuador, 7-6 (7-3), 6-1. The Wimbledon and French Open champion Nadal has won his last five events and is now riding a 32-match winning streak, including a title at last week's Masters Series tournament in Toronto.

Third-seeded Serb Novak Djokovic reached the semifinals with a 6-3, 6-4 triumph over Latvian Ernests Gulbis.

Eighth-seeded Scotsman Andy Murray, rallied to defeat Carlos Moya, who won the Cincinnati championship back in 2002, 2-6, 6-3, 6-1, to advance to his second straight ATP Masters Series semifinal.

Sixteenth-seeded Croatian Ivo Karlovic, who defeated Federer on Thursday, stayed hot with a 7-6 (8-6), 7-6 (7-3) victory over German Philipp Kohlschreiber.

Nadal will meet Djokovic in the semifinals on Saturday, as Murray will face Karlovic in the other half of the semis.

The 2008 titlist here will pocket $420,000.