At the beginning of this week, qualification for the Nitto ATP Finals was realistically possible for four players- David Goffin, Sam Querrey, Kevin Anderson and Pablo Carreno Busta- and minimally so for Juan Martin del Potro, Jo-Wilfried Tsonga and Lucas Pouille. Already, the dream has died for Sam Querrey. The plot thickened further on Tuesday evening when Pablo Carreno Busta placed his chances of competing at the elite season-ending event in a world of peril by losing to Nicolas Mahut 6-4, 6-1 in the second round of the Paris Masters.

Carreno Busta appeared to be in his element in the early stages of the match, buoyed up perhaps by news of Querrey’ shock defeat to Filip Krajinovic just a few hours beforehand. Following one service hold each by both players, Carreno Busta broke in Mahut’s second service game and then held his to take a 3-1 lead. In the fourth game, he came within two points of breaking Mahut again; if it weren’t for the pinpoint accuracy of the 35-year-old’s first serve and acuity around the net, the Spaniard may very well have done so.

Something about fending off the double break unshackled Mahut mentally; he started to come up trumps in both the baseline rallies and the forecourt exchanges in spite of Carreno Busta’s best efforts to frustrate him with his tireless retrieving. Mahut’s go-to weapons- the first serve, biting slice approach shot, and flat, powerful cross court forehand drive- should’ve been vitiated by the high bouncing indoor surface and yet there he was overmatching Carreno Busta from all areas of the court. He broke back to level terms at 3-3 and went 4-3 up with a love game.

Carreno Busta held steady in his next service game and Mahut comfortably won the ninth game, forcing his opponent to serve to stay in the set. With the scoreboard pressure mounting, Carreno Busta fell behind 15-40 but those set points went begging after Mahut shanked a pair of groundstrokes. On his third opportunity to break for the set, Mahut made no mistake, striking a down-the-line forehand that Carreno Busta could not get his racket on.

Mahut won the first game on his serve in the second set and in the next game attacked the Carreno Busta serve with urgency. He hit a clean winner off an inside-out backhand second serve return to bring up two break points. At the first time of asking Mahut converted in style, swatting away Carreno Busta’s first serve with a blistering forehand return winner. Serving at two games to love up, however, the unseeded Frenchman was met with the resistance of a man who wasn’t quite ready to lose yet.

Carreno Busta earned five break points and five times he was denied- four times, in fact, by Mahut’s deadly first serve. That took the wind out of his sails long enough for Mahut to serve-and-volley his way to a 3-0 lead and break Carreno Busta for the second time in the set. Mahut held to win a sixth game in succession, which stretched his lead to 6-4, 5-0. Carreno Busta took his final chance to win a service game but couldn’t manage to find his way into the last of Mahut’s. The 6-1 second set scoreline told the entire story of how dominant Mahut was in the last half hour of the match, besides a brief spot of bother in the third game.

These failures of composure from Querrey and Carreno Busta hand the impetus to Anderson, del Potro and Tsonga to move heaven and earth in their attempts to secure a Nitto ATP Finals berth. David Goffin is expected to qualify in seventh place; in the second round he will have to navigate a way past Adrian Mannarino, who has been playing exquisitely well as of late. I’m no betting man, so I’m not going to predict how events might turn out over the next few days. The one thing that I’m sure of is that it will be one hell of a time to watch it all unfold.