Dudi Sela suffered a first-round exit at a Grand Slam tournament for the first time in more than a year on Monday, falling to American Ryan Harrison in five sets in the opening day of the Australian Open after failing to serve out the match in the fourth set.The 32-year-old Israeli dropped earlier in the day to No. 95 in the world rankings after entering the year’s first major without a victory to his name in 2018. He was knocked out in the first round in the ATP Tour event in Doha to begin the year before losing in the opening round of the ATP Challenger tournament in Canberra, Australia, which he won in 2017.Sela came from behind to take a 2-1 sets advantage over Harrison (45) and broke the American in the ninth game of the fourth set to lead 5-4. But the Israel No. 1 couldn’t clinch the match on his serve, with Harrison winning the next six games to tie the score and then seize control of the encounter, opening a 3-0 lead in the decisive set before securing a 6-3, 5-7, 3-6, 7-5, 6-2 victory after three hours and 39 minutes on Court 22.Tempers flared on several occasions during the match. In the first set, Harrison, agitated by the loud support Sela was receiving, claimed the Israeli had touched a ball in the air on its way out. The players clashed once more in the second set, with the two brushing each other during an exchange of words at a change of ends following the third game.Sela, who began the year at No. 67 but is now set to drop out of the top 100 for the first time since May 2017, reached at least the second round in the three Grand Slams he played last year. He advanced to the second round in Australia and at the US Open, while progressing to the third round in Wimbledon. Sela didn’t play at Roland Garros in 2017, with his last loss in the opening round of a major coming at the US Open in August 2016.Despite the defeat, Sela is hoping to remain in Melbourne for at least a few more days as he is also playing in the doubles tournament with Italy’s Thomas Fabbiano. They will face Max Mirnyi and Philipp Oswald in the first round.Israel’s Yoni Erlich, who will turn 41 in April, is teaming up with 45-year-old Canadian Daniel Nestor, with the veteran duo to play Radu Albot and Hyeon Chung in the opening round. In other first-round action from Down Under, top men’s seed Rafael Nadal and world No. 3 Grigor Dimitrov progressed to the second round of the with easy victories on Monday while top American contenders were sent packing after shock defeats in the first round.World No. 1 Nadal cruised to a 6-1, 6-1, 6-1 win over Dominican Republic’s Victor Estrella Burgos while Dimitrov beat Austrian Dennis Novak 6-3 6-2 6-1 to set up second-round clashes against Leonardo Mayer and Mackenzie McDonald, respectively.Nicole Gibbs was the only American to progress from the women’s draw with last year’s finalist Venus Williams, US Open champion Sloane Stephens and CoCo Vandeweghe being the most notable Americans to exit on day one at Melbourne Park.Harrison and McDonald were the only Americans to progress to the second round of the men’s draw with seeded Jack Sock and John Isner crashing out along with surprise early exits from Croatian Borna Coric and South Africa’s Kevin Anderson.Despite the upsets, the competition remains tough with Caroline Wozniacki, Elina Svitolina and Jelena Ostapenko victorious in their first-round matches along with top men’s players Marin Cilic, Israel- born Denis Shapovalov and Nick Kyrgios.Reuters contributed to this report.