16 deuces, Krishnan broken at 0-2 in 2nd set vs Edberg at '87 USO
11 deuces, Coria broken at 3-5 in the 3rd set vs Nadal at '05 Rome Masters
10 deuces, Blake held at 1-1 in 2nd set vs Fed at '03 USO
10 deuces, Wilander held at 3-2 in the 3rd set vs Edberg at the '87 USO
this link says that Berasategu had a 28 deuce game vs Fillippini at 1996 Casablanca
Alberto Berasategui and Marcelo Filippini recently played what was believed to be the longest single game in ATP Tour history. Filippini was serving at 1-1 in the second set when the game lasted 20 minutes and included 28 deuces. Berasategui took advantage on his 14th break point to break serve and go on to win the match.