[Mr.Michael]

Has there actually ever been a semifinalist with only one victory?

Of course it's happened many times that three players have two victories, but I can't remember a Masters/WTF where three players had one win and advanced to the semis. In doubles that has happened a couple of times, but apparently never in singles?

How is that even mathematically possible?

 

[Voo de Mar]

In singles - no-one got the final, but in doubles Connell and Galbraith won the title in 1995 despite losing two round robin matches (one of them in straight sets!).

 

[Lopez]

Sure it's possible, the first guy (D) wins all 3 and then the rest win against each other: A wins B, B wins C, C wins A with D winning all.

 

[TommyCZE]

Its not ATP finals but its recent: Istanbul WTA finals last month when 3 players finished at 1-2 record (Zvonareva advanced) behind Kvitova (3-0).

 

[gameset&match]

Fat Dave, Shanghai 2006

 

[Mr.Michael]

Fat Dave, Shanghai 2006

Oh yeah, I forgot that one.