(Photo credit: Geoff Burke-Imagn Images)

In his first match since losing an epic semifinal at the Australian Open late last month, second-seeded Jannik Sinner dumped Tomas Machac of the Czech Republic 6-1, 6-4 in the first round of the Qatar ExxonMobil Open on Monday in Doha.

Sinner was the two-time defending Australian Open champion before he fell 3-6, 6-3, 4-6, 6-4, 6-4 to Novak Djokovic in Melbourne. The Italian had no such difficulties on Monday, never facing a break point and committing just nine unforced errors.

Fourth-seeded Daniil Medvedev of Russia, the 2023 Doha champion, also posted a comfortable first-round result, a 6-4, 6-2 victory over China's Juncheng Shang.

Sixth-seeded Jakub Mensik of the Czech Republic beat British qualifier Jan Choinski 6-7 (6), 6-2, 6-4. Australia's Alexei Popyrin and France's Arthur Fils and Valentin Royer also advanced.

Delray Beach Open

Alex Michelsen won 86% of his service points en route to a 7-6 (4), 6-4 victory over sixth-seeded Valentin Vacherot of Monaco in the first round at Delray Beach, Fla.

Michelsen never ceded a break point and was particularly effective when putting his first serve in play, winning 92.3% of the points (36 of 39).

Eighth-seeded Frances Tiafoe of the U.S., the 2018 Delray Beach champ, pushed past Australian qualifier Rinky Hijikata 6-4, 6-4, and the United States' Marcos Giron knocked out Japanese qualifier Sho Shimabukuro 6-3, 7-5. France's Terence Atmane and Hong Kong's Chak Lam Coleman Wong also won their openers.

Rio Open

All three Brazilians in action fell in the first round at Rio de Janeiro.

Peru's Ignacio Buse rallied past Brazilian qualifier Igor Marcondes 4-6, 7-5, 6-4. The Czech Republic's Vit Kopriva defeated Gustavo Heide 6-2, 7-6 (5), and Germany's Yannick Hanfmann beat Joao Lucas Reis Da Silva 7-6 (3), 6-4.

The only seeded player to hit the court on Monday, seventh-seeded Daniel Altmaier of Germany, lost 6-4, 7-6 (7) to Serbia's Dusan Lajovic, a lucky loser from qualifying.

Chile's Alejandro Tabilo and Argentina's Thiago Agustin Tirante moved on with straight-set wins.

--Field Level Media