No fewer than six Americans took the court on Tuesday afternoon in Delray Beach, hoping to avoid the early losses that befell Sam Querrey and Jack Sock on Monday.  Here is a summary of how their fortunes unfolded ahead of the all-American clash on Tuesday night between Michael Russell and John Isner.

Tim Smyczek:  Squaring off against fourth seed Kevin Anderson, Smyczek entered this match as a clear underdog.  His fate recalled Querrey's loss last night.  After seizing a 6-4 first set from his seeded oponent, Smyczek faded quickly while winning just four games over the second and third sets.  He did not earn a break point on Anderson's serve during either of those sets, just as Querrey did not earn a break point in the last two sets against Lopez. 

Bradley Klahn:  The American No. 3 has won two titles at the Challenger level already this year, accounting in part for his rise to world No. 66.  But Klahn could not bring that momentum to the ATP level, routed 6-3 6-1 by eighth seed Lleyton Hewitt.  Toppling a two-time major champion who defeated Roger Federer last month was probably a bridge too far for Klahn in any case.

Steve Johnson:  A nine-ace performance carried the former UCLA star past Mikhail Kukushkin in the most impressive American result of the day.  Johnson had won seven straight matches heading into their encounter, including a title at a high-quality Challenger in Dallas. Unlike Klahn, he managed to extend his winning streak by knocking off an opponent ranked near the top 50.  Johnson, who ranks barely inside the top 150, never dropped his serve in setting up a second-round clash with top seed Tommy Haas.

Wayne Odesnik:  How did Haas reach the second round?  The world No. 12 demolished the 118th-ranked Odesnik for the loss of just three games.  Odesnik never earned a break point and must content himself with two strong wins in qualifying to reach the main draw.  He has spent most of the last several months playing at the Challenger level, and he too has won a title at that level this year.  But a first-round clash with a top seed marked a massive leap in the level of competition.

Ryan Harrison:  Not much was expected of Harrison entering this tournament.  The 21-year-old Florida resident has not yet lived up to his reputation as a potential future star, struggling at not just the ATP but the Challenger level in 2014.  Still, Harrison lived to fight another day in unexpected fashion.  He dropped the first set to Yen-Hsun Lu, only to receive a retirement one game into the second set.  The white-hot Marin Cilic likely looms ahead.

Rhyne Williams:  Like Johnson and Odesnik, Williams qualified for the main draw.  A retirement from Alejandro Falla on Tuesday saw him safely through to the second round.  Williams nearly had clinched victory before Falla retired, and he had produced capable tennis for most of the match.  Dropping serve only once, Williams has lost only 10 games in three matches at Delray Beach between the qualifying draw and the main draw.