Nadal, bidding for his first Key Biscayne title, won 6-2, 5-7, 6-4 in a match that ended shortly after midnight Friday. Tsonga complained during the match and afterward that when borderline calls went against him, umpire Damian Steiner was reluctant to overrule.
"It's not fair," Tsonga said. "If it's really close, he would never say 'out' against Rafa. If Rafa doesn't like him anymore, he would not be in the chair many times in a final and semifinal."
Tsonga said he lost his 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, umpires are less inclined to overrule linesmen.
"I understand sometimes the frustration on this situation," Nadal said. "It's a general thing with the referees today that with the Hawk-Eye, I believe that they feel that they have less pressure than before. Probably knowing that you have the challenge, they don't take the risk to have to overrule.
"He's right in one thing; he's wrong in another thing. "