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Kei Nishikori went unbeaten (5-0) in five-set matches this season.

Top Five Grand Slam Comebacks Of 2019

Nishikori, Cilic among the highlights this season

Continuing our Season In Review series, ATPTour.com looks at the top five comebacks in Grand Slam matches in 2019.

5. Aljaz Bedene d. Benoit Paire, US Open, Second Round (Match Stats)
Aljaz Bedene had never reached the third round in New York and would need to defeat a player he often struggled with in Benoit Paire. The Frenchman led their FedEx ATP rivalry 4-1 and was in the middle of an outstanding season, having won ATP Tour titles in Marrakech (d. Andujar) and Lyon (d. Auger-Aliassime).

Paire served for the match at 5-3 in the fourth set and earned triple match point, but hit a backhand into the net on his first chance. The missed opportunity set off an avalanche of unforced errors and Bedene shockingly won 15 of the next 17 points to bring the match into a decider.

The Frenchman regrouped and raced to a 3-0 lead in the fifth set, but Bedene refused to give in. He scored a break at 2-4 and twice served to stay in the match, sending their clash into a final-set tie-break. The Slovenian’s steady baseline play brought him over the line after a backhand error from Paire wrapped up a 4-6, 6-7(3), 6-2, 7-5, 7-6(4) win after four hours and three minutes.

Bedene fell to Alexander Zverev in an entertaining four-set battle, but rode the momentum to his first tour-level final of the season just three weeks later in Metz (l. to Tsonga).

4. Marin Cilic d. Fernando Verdasco, Australian Open, Third Round (Match Stats)
Marin Cilic and Fernando Verdasco have quietly put together one of the most prolific rivalries on the ATP Tour. Their first FedEx ATP Head2Head match took place in 2007 St. Petersburg (won by Verdasco) and they’ve faced off in 11 of the past 13 seasons. But Cilic walked into Margaret Court Arena with the upper hand in their rivalry (9-5) and had won their past four meetings.

Verdasco appeared ready to turn the tables and held match point at 7/6 in the fourth-set tie-break, but Cilic erased it with a service winner. The crowd gasped as Verdasco then let slip a second match point with a double fault at 8/7. Two points later, a forehand winner from Cilic tied up the score.

The Croatian promptly broke Verdasco and sprinted to a 3-0 lead in the final set. At 12:57 am, he pumped his fist after a forehand error from Verdasco brought him a 4-6, 3-6, 6-1, 7-6(8), 6-3 victory after four hours and 18 minutes. Cilic fired 66 winners en route to prevailing from two sets down for the seventh time in his career.

Cilic lost an entertaining five-set battle in the fourth round to Roberto Bautista Agut and struggled to meet his lofty standards throughout the season. He recorded only one tour-level semi-final (Moscow) and finished the year at No. 39 in the ATP Rankings, but is hard at work in the off-season to climb back up in 2020.

3. Nicolas Mahut d. Marco Cecchinato, Roland Garros, First Round (Match Stats)
Nicolas Mahut was so discouraged about his tennis and fitness prior to Roland Garros that he nearly gave back his wild card. The 37-year-old Frenchman was outside the Top 250 of the ATP Rankings for the first time since 2003 and injuries had limited him to six singles appearances in 2019, most of which were ATP Challenger Tour events on home soil. A back injury convinced Mahut that he should withdraw, but his team persuaded him to rest and the injury gradually improved.

He faced a challenging opening test against Marco Cecchinato, who made headlines with his semi-final run last year at this event and prevailed in February at the Argentina Open (d. Schwartzman). Mahut dropped the first two sets and did not have history on his side, with a 1-38 record after losing the first two sets in the main draw of a Grand Slam.

But with the Parisian crowd unwavering in their support, Mahut dug deep to get himself into the match. After three hours and 18 minutes, Mahut put his hands over his head in disbelief after a backhand sent wide from Cecchinato wrapped up a stunning 2-6, 6-7(6), 6-4, 6-2, 6-4 upset. The match marked Mahut's first Top 20 win at Roland Garros

“For the moment, I'm just enjoying the pleasure of this victory. It is by far my best victory in Roland Garros, in a French tournament. I haven't had many," Mahut said. "Playing on this extraordinary court, I felt that if there was a possibility of playing on this court, it would be incredible and there would be an incredible atmosphere.”

Mahut followed up with a win over Philipp Kohlschreiber, matching his best result at this event, before falling to Leonardo Mayer in four sets. The Frenchman only won two tour-level singles matches after his inspired week in Paris, but enjoyed success in doubles that included titles at the Nitto ATP Finals and Rolex Paris Masters (w/Herbert), in addition to a runner-up finish at Wimbledon (w/Roger-Vasselin).

Read More: Mahut Earns 'By Far His Best Victory' In Paris

2. Hyeon Chung d. Fernando Verdasco, US Open, Second Round (Match Stats)
Hyeon Chung endured a frustrating series of injuries after reaching his maiden Grand Slam semi-final at the 2018 Australian Open. He arrived in New York in the early stages of another comeback after missing six months due to a back injury. The South Korean was forced to qualify for the final Grand Slam of the year, but powered into the main draw without dropping a set and scored a five-set win in his opening round against Ernesto Escobedo

It appeared the volume of matches would be too much for Chung after he dropped the first two sets in 58 minutes during his second-round clash with Fernando Verdasco. But as Chung mounted a comeback and eventually forced a fifth set, Court 10 became standing room only and the crowd were largely on his side. 

Verdasco broke Chung for a 3-1 lead in the decider and served for the match at 5-3, but the two-time US Open quarter-finalist pushed a forehand volley long to bring the match back on serve. As the crowd roared in approval, the normally mild-mannered Chung threw his arms up in the air and encouraged them to make more noise.

Chung saved a match point on his serve at 5-6 and then stormed through the tie-break to complete an incredible 1-6, 2-6, 7-5, 6-3, 7-6(3) comeback after three hours and 22 minutes. The South Korean spent a minute under seven hours on court in his first two rounds, proving he was fully recovered from his back injury.

Chung fell to eventual champion Rafael Nadal in the third round, but went on to score high-profile wins over Cillic and Milos Raonic in the latter stages of the season. With only 45 ATP Rankings points to defend until July, he's primed to make a significant climb next year.

1. Kei Nishikori d. Pablo Carreno Busta, Australian Open, Fourth Round (Match Stats)
Kei Nishikori's journey into the second week cemented his status as Melbourne's marathon man. He survived a pair of five-set matches in his first two rounds, rallying from two sets down against Kamil Majchrzak and then defeating Ivo Karlovic in a fifth-set tie-break.

After Pablo Carreno Busta prevailed in the first two sets and broke Nishikori for a 3-2 lead in the third set, it seemed that the hours on court had finally taken their toll on the Japanese. But Nishikori clawed back to take the third set and found the range on his serve, scoring three love holds in the fourth set en route to forcing a decider.

The vocal crowd watched as Nishikori broke for a 2-1 lead in the final set, but he got tight when serving for the match at 5-4 and gifted the break back to the Spaniard. The battle eventually reached what was just the third final-set tie-break in tournament history for men's singles.

Carreno Busta was rewarded for taking the initiative in their baseline rallies and grabbed a commanding 8/5 lead, but Nishikori charged back and won the last five points of the match. The Japanese star finished with an ace — his 15th of the match — to improve to 21-7 in five-setters.

"I don't even know how I came back," Nishikori said. "But [I'm] very happy to win today."

At five hours and five minutes, Nishikori and Carreno Busta put on the fifth-longest Open Era match in tournament history. Nishikori finished the night with a staggering 81 winners to 57 unforced errors. 

After 18 sets of tennis in a week, his body surrendered and he retired due to injury midway through the second set of his quarter-final with Novak Djokovic. Nishikori's injury woes resurfaced when a right elbow injury shut down his season after the US Open. He underwent surgery for the injury in October, but expects to be ready to start next season by representing Japan in the inaugural ATP Cup, held in Australia from 3-12 January.