Jo-Wilfried Tsonga beaten as Kevin Anderson, Borna Coric advance at Winston-Salem Open

The French third seed sent down 13 aces but went down 6-3 4-6 7-6 (7-4) to the American at the ATP 250 event played on hard courts.

Tsonga was left to rue missed opportunities as he converted just one of seven break points to lose in one hour, 58 minutes.

Johnson will face Lu Yen-hsun, who battled past Chung Hyeon 7-6 (7-1) 1-6 7-5.

The pick of the quarter-finals comes in the bottom half of the draw, with second seed Kevin Anderson to meet Croatian teenager Borna Coric.

Anderson served 17 aces on his way to securing a 7-6 (7-2) 6-4 victory over Pole Jerzy Janowicz - last year's runner-up in North Carolina.

Coric, the eighth seed, was completely untroubled as he cruised past Diego Schwartzman, thrashing the Argentine 6-2 6-1.

Aljaz Bedene was unable to back-up his shock win over Gilles Simon, the Brit losing 6-3 6-0 to French qualifier Pierre-Hugues Herbert.

Herbert will meet Pablo Carreno Busta after the Spaniard's 6-4 4-6 6-1 win against Italian Simone Bolelli.

Thomaz Bellucci got the better of Jiri Vesely in the battle of the left-handers, winning 6-1 6-7 (7-9) 6-4 to set up a clash against Malek Jaziri, who defeated Teymuraz Gabashvili 7-5 6-4.