Tatsuma Ito and Michal Przysiezny claimed the biggest wins of their careers at the Japan Open on Tuesday when the local wildcard knocked out top seed Stan Wawrinka and the Polish qualifier saved match points to beat Jo-Wilfried Tsonga.
World number 103 to sealed the stunning 7-5, 6-2 first-round victory on his second match point, cushioning a backhand volley into an open court after his wide serve had forced Wawrinka out of position.
"I played a very good match," Ito said. "It is the first time I have beaten a top-five player.
"I tried my best every point and I was very focused. I was a little nervous, but I stuck to my game and I finished well."
Australian Open winner Wawrinka struggled throughout the contest at the ATP 500 event, dropping serve four times and hitting 25 unforced errors in his first tour event since losing to Ito's compatriot Kei Nishikori at the U.S. Open this month.
Wawrinka, who helped Switzerland reach the Davis Cup final two weeks ago, lost his serve in the third game on the Tokyo hard court, only to break back and hold for a 5-4 lead in the first set.
The loss delays Wawrinka's bid to qualify for the season-ending ATP World Tour Finals
However, the 29-year-old failed to take advantage as the Japanese, who has never made an ATP final and had only two previous wins on tour this year, took the set and an early lead in the second with a run of five straight games.
Wawrinka threatened a break back at 3-2 down but the busy Ito, wearing his baseball cap back to front, survived the scare and broke the Swiss once again as he confidently finished off the match against a dejected opponent.
"It was not a good day at the office. He started well and then I was trying to come back in the match," Wawrinka said.
"First-round matches are never easy. He played well, particularly at the end of the first set when he was very aggressive."
The loss delays Wawrinka's bid to qualify for the season-ending ATP World Tour Finals in London, which the Swiss could have achieved had he reached the final in Tokyo.
He is fourth in the race for one of the eight spots available at the November event.
Tsonga also looked like retiring
Ito, 26, has no hope of making it to London but will instead look forward to a second-round clash against German Benjamin Becker, who advanced after Finn Jarkko Nieminen retired from their match through fatigue when trailing 7-5 4-1.
Sixth seed Roberto Bautista Agut also failed to go the distance in his match, the Spaniard pulling out with a thigh injury after blowing six match points against Gilles Simon of France.
Simon led 4-6, 7-6(7), 2-1 when his opponent called it a day.
Tsonga also looked like retiring when he called for the trainer because of an issue with his right wrist when trailing 3-0 in the deciding set against his 142nd-ranked Polish opponent.
The break did the 2009 champion good, though, as he clawed back the deficit and forced a tiebreak but the Frenchman wasted three match points as 30-year-old Przysiezny hung tough to record a 4-6 7-5 7-6(9) upset win at the Ariake Coliseum.
The loss left Tsonga, 12th in the race to London, facing a tough ask to qualify for the ATP World Tour Finals after he followed seventh-placed David Ferrer, who lost in three sets on Monday, in making a first-round exit in Japan.
Li named ambassador for WTA Finals in Singapore
Recently retired Chinese tennis trailblazer Li Na, Asia's only Grand Slam singles winner, has been appointed as an ambassador for next month's season ending WTA Tour Finals in Singapore.
The 32-year-old was in position to qualify for the lucrative October 17-26 tournament before announcing she was quitting a fortnight ago after being worn down by the effects of long-term knee injuries.
This year's Australian Open winner and the 2011 French Open champion will take on her new role for the first two editions of the event, which is switching to Singapore next month for the start of a five-year term.
"This will be a great opportunity for the fans from around the world over to get close to a tennis legend who has inspired a nation and done so much for the game in Asia Pacific," WTA Chairman & CEO Stacey Allaster said in a statement.
"She has inspired a generation of young girls throughout Asia-Pacific with hopes that, they too, can achieve the dream of playing in the WTA Finals."
The top eight women's singles and doubles teams will take part in Singapore, only the second Asian country to stage the event after Qatar hosted three editions from 2008.
How retail therapy works best for Thai golf trio
Sania-Myneni win mixed doubles gold at Asian Games
Seema Punia wins Asian Games discus gold
Sania happy to mentor India's rising tennis stars
Govt cuts import tariff value on gold, silver