(Photo credit: Jonathan Hui-Imagn Images)

Italy's Matteo Arnaldi saved four match points en route to a 4-6, 6-2, 7-6 (2) comeback win over Germany's Daniel Altmaier in the opening round of the Mubadala Citi D.C. Open on Monday in Washington.

Arnaldi faced triple match point in the 10th game of the third set but battled back to extend the match. Then, Arnaldi led 6-5 only for Altmaier to save two match points and force the tiebreaker, which was all Arnaldi. The 24-year-old reached the quarterfinals of the Madrid Open but is still searching for his first ATP title.

Reilly Opelka also got off to a fine start by defeating Murphy Cassone 7-6 (4), 6-7 (5), 6-3. This one did not see a match point saved, but Opelka served up 23 aces in the two-hour, 21-minute affair and won a whopping 53 of 61 first-service points (86.9 percent).

Americans who joined Opelka as winners on Monday included Mackenzie McDonald, Ethan Quinn and Learner Tien. Hungarian Fabian Marozsan, Frenchman Alexandre Muller and Brits Cameron Norrie and Daniel Evans also advanced.

In the final two matches of the night, Japan's Yoshihito Nishioka clawed past Jenson Brooksby 6-4, 5-7, 6-1, and Australia's Aleksandar Vukic pulled out a 6-4, 3-6, 6-3 win over France's Giovanni Mpetshi Perricard.

Generali Open

No. 6 seed Arthur Rinderknech of France survived a test from Argentina's Facundo Bagnis and prevailed 7-6 (4), 4-6, 6-3 in a two-hour, 47-minute marathon in the Round of 32 in Kitzbuhel, Austria.

The other seeded players in action also survived: No. 7 seed Francisco Comesana of Argentina beat Tristan Boyer 6-3, 7-6 (1), and No. 8 Marton Fucsovics of Hungary outlasted Austrian wild card Joel Schwaerzler 6-2, 2-6, 6-3.

Slovakian qualifier Norbert Gombos survived Frenchman Hugo Gaston 6-3, 6-4, and Kazakhstan's Alexander Shevchenko rallied past Daniel Elahi Galan of Colombia 2-6, 6-3, 6-4.

Plava Laguna Croatia Open

Stan Wawrinka of Switzerland cruised past Venezuelan qualifier Alvaro Guillen Meza 6-4, 6-1 in his first-round match in Umag, Croatia.

The three-time Grand Slam champ hasn't won an ATP tournament since May 2017. His next opponent will be No. 4 seed Damir Dzumhur of Bosnia and Herzegovina, who had a first-round bye.

No. 5 Mariano Navone of Argentina sped past Chile's Tomas Barrios Vera 6-1, 6-2 in 70 minutes, but other seeded players weren't as lucky. Georgia's Nikoloz Basilashvili toppled No. 6 Roberto Carballes Baena of Spain 6-3, 6-4, and Spanish qualifier Pablo Llamas Ruiz beat No. 7 Kamil Majchrzak of Poland 6-3, 6-4. Also advancing were Frenchmen Terence Atmane and Titouan Droguet, Spaniard Carlos Taberner and Taiwan's Chun-Hsin Tseng.

--Field Level Media