German tennis player Jan-Lennard Struff stunned No. 2 seed Jo-Wilfried Tsonga to reach the St. Petersburg Open semi-finals. The world No. 54 created a comeback to beat the Frenchman 3-6 6-3 6-2. Tsonga was on the verge of reaching the last-four stage but fell short in the end.

Struff has defeated the former Wimbledon semifinalist for the first time in his career. The head-to-head record between the German and Tsonga now stands at 3-1 in favor of the Frenchman. Previously, Tsonga beat Struff in straight sets in Marseille in 2014, at the Monte Carlo Masters in 2015, and at the French Open a year ago.

Tsonga was cruising to victory

Tsonga opened up an early 4-1 first set lead. Struff had a break point in the seventh game, which he didn't convert. The Frenchman later routinely served out for the set in the ninth game. Tsonga then opened the second set on a good tale as well. The Frenchman had a 3-1 lead when he just turned off. Struff won the last games of the set to force a decider. Tsonga regrouped a bit after a second set shock. Tsonga was up by 2-1 after the first three games of the third set. He had a break point to open up a 3-1 lead but didn't convert. Once again, Tsonga's game suddenly fell apart, as Struff won five games in a row to seal the St. Petersburg Open semi-finals.

Match stats

Struff hit five aces and won 78 percent of his first serve points in St. Petersburg on Friday. The German converted 4-of-8 of his break point tries and also saved 2-of-4 of Tsonga's break point chances. The match came to an end after an hour and 48 minutes of play.

Struff plays next Dzumhur

Struff is now set to Bosnian Damir Dzumhur in the St.

Petersburg semi-finals. The two have no previous meetings at the ATP level. However, they met at the Challenger event in Alphen aan den Rijn a year ago. Back then, Struff was up by 4-0 in the third set when Dzumhur retired the clash. Struff recently lost in the Winston-Salem semi-finals to Spain's Roberto Bautista Agut. On the other side, Dzumhur fell short in the Los Cabos last-four stage to eventual champion Sam Querrey.

Dzumhur prevailed over British sensation Liam Broady in the opening match of the day in St. Petersburg. Dzumhur handed a 6-3 2-6 6-4 defeat to the world No. 242. Broady had a 2-0 lead in the third set before Dzumhur regrouped to book a ticket for the semi-finals. Dzumhur converted 5-of-10 of his break point chances and saved 8-of-12 of Broady's break point tries. The match touched the finish line after an hour and 52 minutes of action.