Top seed Alexander Zverev survived a dramatic five-set battle against Italy’s Lorenzo Sonego to reach the second round of the US Open.

Zverev eventually prevailed 6-4, 3-6, 6-7(7), 7-5, 6-4 in a contest that lasted almost five hours and continued into the early hours of Wednesday.

The German arrived in New York carrying increased expectations after winning the French Open in June, his first Grand Slam title.

With world number one Jannik Sinner absent and defending champion Carlos Alcaraz returning from a lengthy injury layoff, Zverev entered the tournament as one of the leading contenders.

But world number 89 Sonego pushed the top seed to the limit from the opening stages.

Zverev converted only one of seven break-point opportunities in the first set, although that proved enough for him to take it 6-4.

Sonego responded strongly in the second set.

The Italian secured an early break, maintained the advantage and closed out the set to love with an ace to level the match.

The third set developed into an even tighter contest and eventually required a tiebreak.

A costly double fault from Zverev helped Sonego seize the opportunity, allowing the Italian to move two sets to one ahead.

The pressure increased further in the fourth set as the players exchanged breaks.

At one stage, Zverev found himself only two points away from elimination.

The German managed to hold serve at the crucial moment before breaking Sonego late in the set to force a deciding fifth.

Zverev gradually gained the upper hand in the final set as the physical demands of the lengthy contest began to take their toll on Sonego.

The top seed secured the decisive advantage and completed the comeback 6-4 in the fifth.

The victory allowed Zverev to avoid becoming the first top seed to lose in the opening round of a Grand Slam since Lleyton Hewitt at Wimbledon in 2003.

After the match, Zverev said his main feeling was relief at having survived such a demanding contest.

He described the encounter as an extraordinary battle filled with momentum swings and said it was likely the longest first-round Grand Slam match of his career.

Zverev also praised Sonego’s performance, saying the Italian had produced a level capable of defeating many opponents.

Despite the difficult night, Zverev said surviving such matches can be valuable during a major tournament.

The French Open champion will next face France’s Quentin Halys as he continues his pursuit of a second Grand Slam title.