Melbourne - Fifth seed Kevin Anderson was sent packing from the Australian Open in round two on Wednesday with American Frances Tiafoe prevailing 4-6, 6-4, 6-4, 7-5.
The South African, a Wimbledon finalist last year, struggled with an elbow injury early in the clash and couldn't cope with Tiafoe's power and finesse.
World number 39 Tiafoe, who is into the third round at Melbourne Park for the first time, equalling his best ever Grand Slam result, next plays veteran Italian Andreas Seppi.
"It means the world to me," said the American, who will celebrate his 21st birthday on Sunday and is fresh from playing the mixed teams Hopman Cup in Perth with Serena Williams.
"I lost to him three times last year and when I was down a set and a break it looked like it would happen again. I dug deep and went to a different place.
"It's all about competing, how bad you want it and I want it real bad. I'd love to get to the second week of a Slam for the first time," he added.
Anderson warmed up for the Australian Open by winning his sixth ATP title at Pune earlier this month, defeating Croat veteran Ivo Karlovic in the final.
He had been looking for a deep run at Melbourne Park this year after getting past the opening round for the first time since 2015.
Meanwhile, South Africa's other participant in the men's singles, Lloyd Harris, suffered a heavy defeat at the hands of Russia's Daniil Medvedev in the first round on Tuesday.
The 21-year-old Harris, who qualified for the main draw, was beaten 6-1, 6-2, 6-1 by the 15th-seeded Russian.
In the men's doubles, South Africa's Raven Klaasen and his New Zealand doubles partner Michael Venus opened their campaign with a 4-6, 6-4, 6-3 win against American Bradley Klahn and Kazakhstan’s Mikhail Kukushkin.
Klaasen and Venus are the sixth seeds.
Results from Day 3 of the Australian Open on Wednesday:
Stefanos Tsitsipas (GRE x14) bt Viktor Troicki (SRB) 6-3, 2-6, 6-2, 7-5
Nikoloz Basilashvili (GEO x19) bt Stefano Travaglia (ITA) 3-6, 6-3, 3-6, 6-4, 6-3
Tomas Berdych (CZE) bt Robin Haase (NED) 6-1, 6-3, 6-3
Andreas Seppi (ITA) bt Jordan Thompson (AUS) 6-3, 6-4, 6-4
Diego Schwartzman (ARG x18) bt Denis Kudla (USA) 6-4, 7-5, 3-6, 6-7 (6/8), 6-4
Marin Cilic (CRO x6) bt Mackenzie McDonald (USA) 7-5, 6-7 (9/11), 6-4, 6-4
Frances Tiafoe (USA) bt Kevin Anderson (RSA x5) 4-6, 6-4, 6-4, 7-5
Fernando Verdasco (ESP x26) bt Radu Albot (MDA) 6-1, 7-6 (7/2), 6-3
Karen Khachanov (RUS x10) bt Yoshihito Nishioka (JPN) 6-3, 6-3, 6-3
Roger Federer (SUI x3) bt Daniel Evans (GBR) 7-6 (7/5), 7-6 (7/3), 6-3
Taylor Fritz (USA) bt Gael Monfils (FRA x30) 6-3, 6-7 (8/10), 7-6 (8/6), 7-6 (7/5)
Roberto Bautista Agut (ESP x22) bt John Millman (AUS) 6-3, 6-1, 3-6, 6-7 (6/8), 6-4
Grigor Dimitrov (BUL x20) bt Pablo Cuevas (URU) 6-3, 6-7 (5/7), 6-3, 7-5
Thomas Fabbiano (ITA) bt Reilly Opelka (USA) 6-7 (15/17), 6-2, 6-4, 3-6, 7-6 (10/5)
Alex de Minaur (AUS x27) bt Henri Laaksonen (SUI) 6-4, 6-2, 6-7 (7/9), 4-6, 6-3
Rafael Nadal (ESP x2) bt Matthew Ebden (AUS) 6-3, 6-2, 6-2
Sloane Stephens (USA x5) bt Timea Babos (HUN) 6-3, 6-1
Petra Martic (CRO x31) bt Marketa Vondrousova (CZE) 6-4, 7-5
Aliaksandra Sasnovich (BLR) bt Anett Kontaveit (EST x20) 6-3, 6-3
Caroline Garcia (FRA x19) bt Zoe Hives (AUS) 6-3, 6-3
Ashleigh Barty (AUS x15) bt Wang Yafan (CHN) 6-2, 6-3
Anastasia Pavlyuchenkova (RUS) bt Kiki Bertens (NED x9) 3-6, 6-3, 6-3
Amanda Anisimova (USA) bt Lesya Tsurenko (UKR x24) 6-0, 6-2
Maria Sakkari (GRE) bt Astra Sharma (AUS) 6-1, 6-4
Danielle Collins (USA) bt Sachia Vickery (USA) 6-3, 7-5
Caroline Wozniacki (DEN x3) bt Johanna Larsson (SWE) 6-1, 6-3
Kimberly Birrell (AUS) bt Donna Vekic (CRO x29) 6-4, 4-6, 6-1
Petra Kvitova (CZE x8) bt Irina Begu (ROU) 6-1, 6-3
Belinda Bencic (SUI) bt Yulia Putintseva (KAZ) 7-5, 4-6, 6-2
Aryna Sabalenka (BLR x11) bt Katie Boulter (GBR) 6-3, 6-4
Angelique Kerber (GER x2) bt Beatriz Haddad Maia (BRA) 6-2, 6-3