Sam Querrey's slim chances for a spot in the ATP Tour Finals ended at the Paris Masters as the American lost 6-4 6-4 to qualifier Filip Krajinovic.
Californian Querrey stood provisional 11th going into his second-round match with the Croatian, and is now out of contention.
The last two places for the eight-man field at the ATP Finals in London from November 12 will be decided this week at Bercy.
Still chasing a possible spot is Spaniard Pablo Carreno Busta, who was later facing Nicolas Mahut of France.
Already qualified into the year-end field are Paris top seed Rafael Nadal, Roger Federer, German Alexander Zverev, Dominic Thiem, Marin Cilic and Grigor Dimitrov.
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Chasing for the next position is Belgian David Goffin, who stands ahead of Carreno Busta, while Kevin Anderson, Juan Martin del Potro and Jo-Wilfried Tsonga all likely have to win the Paris tournament to qualify.
The first round wrapped up as Briton Kyle Edmund staged a comeback to beat Russian Evgeny Donskoy 5-7 7-6 (9-7) 6-3 in a struggle lasting for almost two and a half hours as the pair combined for 22 aces.
Spanish veterans Feliciano Lopez and Fernando Verdasco both advanced.
Lopez defeated Frenchman Pierre-Hugues Herbert 7-6 (7-4) 6-3 while Verdasco dispatched young Russian Andrey Rublev 7-6 (7-1) 7-6 (8-6)
Diego Schwartzman, finalist this month at Antwerp against Tsonga, stopped Serb Viktor Troicki 6-3 6-4 while local Adrian Mannarino schooled Spain's former top 10 regular David Ferrer, the 2012 Bercy winner, 6-2 6-4 in just over 90 minutes.
Pablo Cuevas of Uurguay beat Karen Khachanov of Russia 6-4 6-2, Portugal's Joao Sousa sent out Italian Paolo Lorenzi 6-4 7-5 and Croatian Borna Coric defeated German Jan-Lennard Struff 6-3 6-4.
