Melbourne - Jeremy Chardy reached the round of 16 for the first time at the Australian Open with a fighting five-set win over sixth seed Juan Martin Del Potro on Saturday.
The 36th-ranked Frenchman raced to a two sets to love lead, before Del Potro pulled back to level the match only to prevail 6-3, 6-3, 6-7 (3/7), 3-6, 6-3 in 3hr 45min on Hisense Arena.
Chardy was ecstatic to have beaten the former US Open champion and will now face Italian 21st seed Andreas Seppi in an unexpected fourth round matchup on Monday.
Seppi upset Croatian 12th seed Marin Cilic in another five-setter.
"I played my best tennis to get to two sets to love, then he came back, so I tried to forget it and stay focused on my serve," Chardy said.
"I thought if I had a chance to break him I had to go for it and I did and I'm so happy.
"I think it's maybe the best win because it's in the Grand Slam at the Australian Open in the third round against a top player."
Chardy's forehand was his big weapon with 44 winners along with 20 aces in his an overall total of 78 winners.
Del Potro, who was playing in his first official tournament of the year, has yet to win from two sets down and he was under pressure from the outset with a service break in the second game.
The big Argentinian staved off three set points at 2-5 but the hot Frenchman clinched the opening set on his fourth set point with a cracking forehand winner.
Del Potro was off his game and was broken again in the fifth game of the next set and was two set points down in the ninth game when he netted a forehand to go two sets behind.
He finally broke Chardy's service in the opening game of the third set only to give it back in the following game.
The sixth seed fought off four break points in the sixth game before taking the third set to a tie-breaker.
He relished the chance and powered to the set on the back of two mini-breaks as Chardy began to look vulnerable.
Del Potro broke Chardy's serve in the eighth game and served out to level the match in the fourth set.
But Del Potro gave Chardy his chance with a weak service game in the eighth game of the final set and was broken was he put a forehand wide.
Chardy served it out and sealed victory with an ace.
Latest results from day six of the Australian Open on Saturday:
Maria Kirilenko (RUS x14) bt Yanina Wickmayer (BEL x20) 7-6 (7/4), 6-3
Svetlana Kuznetsova (RUS) bt Carla Suarez Navarro (ESP) 6-2, 4-6, 6-3
Victoria Azarenka (BLR x1) bt Jamie Hampton (USA) 6-4, 4-6, 6-2
Serena Williams (USA x3) bt Ayumi Morita (JPN) 6-1, 6-3
Elena Vesnina (RUS) bt Roberta Vinci (ITA x16) 4-6, 7-6 (7/4), 6-4
Caroline Wozniacki (DEN x10) bt Lesia Tsurenko (UKR) 6-4, 6-3
Sloane Stephens (USA x29) bt Laura Robson (GBR) 7-5, 6-3
Richard Gasquet (FRA x9) bt Ivan Dodig (CRO) 4-6, 6-3, 7-6 (7/2), 6-0
Jeremy Chardy (FRA) bt Juan Martin Del Potro (ARG x6) 6-3, 6-3, 6-7 (3/7), 3-6, 6-3
Jo-Wilfried Tsonga (FRA x7) bt Blaz Kavcic (SLO) 6-2, 6-1, 6-4
Andreas Seppi (ITA x21) bt Marin Cilic (CRO x12) 6-7 (2/7), 6-3, 2-6, 6-4, 6-2
Andy Murray (GBR x3) bt Ricardas Berankis (LTU) 6-3, 6-4, 7-5