Aljaz Bedene upset top seed Gilles Simon at the Winston-Salem Open as Lukas Rosol saw his title defence ended.

Simon, the top seed at the ATP 250 event played on hard-courts, suffered a 6-7 (5-7) 7-6 (7-5) 7-6 (8-6) loss to Brit Bedene in just under three hours.

Bedene was a set and 3-1 down before fighting back, only to find himself struggling once more in the third set.

He saved two match points in the ninth game of the third and then broke back when Simon was serving for it at 5-4, before winning the tie-break to complete his comeback.

Bedene will face Pierre-Hugues Herbert in the third round after the French qualifier overcame Marcos Baghdatis 6-3 2-6 7-5.

Defending champion Rosol had his title defence ended by Jerzy Janowicz as the Pole cruised to a 6-3 6-2 victory, in a re-match of the 2014 final.

There were no such problems for second seed Kevin Anderson and third seed Jo-Wilfried Tsonga.

Anderson got past Mikhail Kukushkin 4-6 6-2 6-3 and Tsonga made it five wins from five meetings with Denis Istomin courtesy of a 5-7 6-4 6-1 victory.

Seeds to fall included Benoit Paire, Guillermo Garcia-Lopez, Viktor Troicki, Pablo Andujar and Joao Sousa.

Paire went down to Chung Hyeon 6-1 6-4, Lu Yen-hsun beat Garcia-Lopez 6-3 6-3, Malek Jaziri overcame Troicki 6-4 4-6 6-4 and Diego Schwartzman battled past Andujar 4-6 7-5 7-5.

Sousa was comfortably beaten by Pablo Carreno Busta 6-4 6-4.

American 13th seed Steve Johnson served 15 aces on his way to a 6-4 6-7 (4-7) 6-1 win over Australian Sam Groth.

Teenage qualifier Frances Tiafoe went close to an upset before losing to Thomaz Bellucci 6-3 2-6 7-6 (7-2).

Jiri Vesely claimed a 6-3 6-4 win over Martin Klizan and Teymuraz Gabashvili needed three hours to edge Australian Thanasi Kokkinakis 7-6 (7-5) 6-7 (5-7) 7-6 (7-3).