Tuesday saw the completion of the opening round of the singles draw at the ATP Challenger Orlando Open Presented by Nemours. A trio of doubles matches was also contested on day two of the event.

Two major upsets highlighted the day’s singles action. American Christopher Eubanks scored a huge victory in a matchup of former collegiate standouts, stunning top-seeded and fellow American Steve Johnson 6-1, 7-6(3). Eubanks served up 15 aces over the course of the match despite making just 54% of his first serves. He was also extremely successful in the points which started on the second service of Johnson, with Eubanks taking 12 of those 19 points. For the match, Eubanks secured four breaks of serve. Next up for him is Michael Mmoh (United States), who outlasted American qualifier Martin Damm 6-4, 4-6, 6-1.

In another all-American matchup, Christian Harrison downed No. 3 seed Mackenzie McDonald 7-5, 6-3. Harrison protected his serve with great success, finishing with an impressive 73% winning percentage of his first-serve points while also saving seven of the eight break points he faced. Harrison managed to break McDonald four times on the day. It will be a clash of American wild cards in the second round when Harrison meets Aleksandar Kovacevic after the University of Illinois senior fought his way past qualifier Roberto Quiroz (Ecuador) 6-1, 5-7, 6-4.

Second seed Yasutaka Uchiyama (Japan) narrowly avoided being eliminated by Canadian Peter Polanksy, eventually prevailing 6-3, 3-6, 6-4. Both players stayed strong on serve from start to finish in a match that last nearly 2.5 hours, with just one break proving the difference in each of the three sets. Uchiyama will be across the net from wild card Zane Khan (United States) after his 6-3, 1-6, 6-1 victory against lucky loser and countrymen Kevin King.

In other results from Tuesday, qualifier Tim Van Rijthoven (Netherlands) kept his run going thanks to a 6-3, 6-4 effort over American Mitchell Krueger. He will take on another American, No. 5 Denis Kudla, in his next match; Kudla cruised past Joao Menezes (Brazil) 6-2, 6-2. It was a better day for another Brazilian competitor, as fourth-seeded Thiago Seyboth Wild dominated Facundo Mena (Argentina) 6-2, 6-0. Next up for Seyboth Wild is Roberto Cid Subervi of the Dominican Republic, who held off Denmark’s Mikael Torpegaard 7-6(2), 6-3.

Sixth-seeded Prajnesh Gunneswaran (India) got his week off to a solid start, defeating Australian Matthew Ebden 6-4, 6-1. American Jack Sock awaits him in the round of 16 following his comprehensive 6-1, 6-1 victory versus Yosuke Watanuki (Japan). Qualifier Altug Celikbilek (Turkey) also came through with a complete effort against American Thai-Son Kwiatkowski, prevailing 6-2, 6-3; Celikbilek is set to take on Jenson Brooksby (United States) next.

Two seeded doubles tandems were also upset on Tuesday. The American wild card pairing of Alexander Ritschard and Alex Rybakov won a marathon over No. 4 seeds N. Sriram Balaji and Jeevan Nedunchezhiyan of India 6-7(4), 6-4, 18-16. Additionally, second seeds Evan King and Hunter Reese were upended by wild card duo Sekou Bangoura and Junior Ore 6-4, 6-4 in a showdown of American teams. Also moving on to the quarterfinal stage was Menezes and Seyboth Wild after they staged a 3-6, 6-4, 10-5 comeback over American Bjorn Fratangelo and Jason Jung (Chinese Taipei).

For more information on the ATP Challenger Orlando Open Presented by Nemours, click here. Wednesday’s full schedule of play can be viewed here.