Rafael Nadal, Andy Murray advance

No. 2-seeded Rafael Nadal continued his bid for his first Key Biscayne title, defeating No. 6 Jo-Wilfried Tsonga 6-2, 5-7, 6-4 in the Sony Ericsson Open men's quarterfinals Wednesday.

Controversy followed the match, as Tsonga claimed that Nadal received preferential treatment from the chair umpire, a claim Nadal disputed.

Tsonga complained during the match and afterward that umpire Damian Steiner was reluctant to overrule borderline calls.

Tsonga said he lost concentration because he became so focused on watching the lines in case he needed to challenge a ruling.

Many players contend that since the advent of the Hawk-Eye replay review system, which allows players to challenge calls, umpires are less inclined to overrule the linesperson.

Nadal's opponent Friday will be 2009 champion Andy Murray, who overcame an upset stomach and early deficit to beat No. 9 Janko Tipsarevic 4-6, 6-3, 6-4.

Murray defeated Gilles Simon in straight sets on Tuesday to reach the quarterfinals.

Information from The Associated Press was used in this report.