In an unusual step, the Tennis Integrity Unit - which polices match-fixing on the professional tour - has announced it is investigating an ATP match only a matter of hours after play concluded.
The match in question took place on Monday, in the first round of North Carolina's Winston-Salem Open, where Alexandr Dolgopolov was defeated 6-3, 6-3 by Thiago Monteiro - a player ranked 51 places below him at No114 in the world.
The result might have been a minor upset, on paper. But the more surprising thing was the way that the odds shifted a couple of hours before the players went on court.
Monteiro had started as a 3-1 outsider on some exchanges, but the roles soon reversed - a sign that significant money was being gambled on the underdog - so that it was Dolgopolov who became the less-favoured player.
Responding to these anomalous betting patterns, a number of bookmakers suspended any betting on the match before it had even begun.
Then Dolgopolov failed to produce the sort of tennis that might have been expected from a talented strokeplayer who once stood as high as No13 in the world.
According to Ian Dorward, a betting expert who was among the first to draw attention to the match, Dolgopolov failed to generate a single break point on the Monteiro serve - something that had only previously happened in his career when he was playing against Roger Federer.
As Dorward added: "It is the first time in Monteiro's career that he has not faced a single break point on a hard court. In his previous seven hard-court matches at ATP level, he had been broken 31 times."
An official statement said: "The TIU was made aware of concerns over betting patterns during the match ... As with all match alerts, the TIU will assess, make a judgment and take appropriate action on the information received through its co-operative agreements with betting operators."
Dolgopolov - who is 28 and comes from Ukraine - has previously acknowledged that he was among a group of players who received letters from the TIU soon after its foundation in 2010, but he has never been officially censured.