World number two Carlos Alcaraz maintained his quest for a second US Open title with a straight-set victory over unseeded Frenchman Arthur Rinderknech in the fourth round.

The 22-year-old, who is through to the last eight in New York for the fourth time in five years, is yet to drop a set at this year's tournament, coming through 7-6 (7-3) 6-3 6-4.

The Spaniard will face Jiri Lehecka in the quarter-finals after the Czech 20th seed beat Adrian Mannarino in four sets.

Alcaraz had to be at his magical best at times, producing 36 winners to 11 unforced errors, chasing down several drop shots and even producing an extravagant round-the-back return to counter Rinderknech's attacking approach.

Despite both players serving below 50% on their first serves, there wasn't a single break point in a tight opening set, with Alcaraz eventually taking the tie-break 7-3.

An untimely double-fault from Rinderknech, who hit 17 unforced errors in the first set, sparked a run of five successive points for his opponent, who then converted the second of his four set points.

"The first set was tight. We didn't have break points and it didn't mean we were serving well - the percentage was bad from both us," Alcaraz said.

"But after that, I got in a good rhythm and tried to make the most of opportunities.

"I played good, aggressive tennis and found a good rhythm after the second set and tried to keep it going."

Addressing his trick shots, he added, "Sometimes I practice them, I'm not going to lie!

"If I have the opportunity, why not? The people like it, I like playing tennis like this, it just comes naturally."

The 2022 champion had to wait until the sixth game of the second set for his first break points of the match, converting the second with a smash winner to take a 4-2 lead.

He then wobbled on his serve to hand Rinderknech two opportunities of his own, but held firm before closing out the second set 6-3.

Rinderknech halted Alcaraz's momentum in the opening game of the third, saving a break point with a deft backhand volley, and with both players having rediscovered their first serves, the set seemed destined for a tie-break.

However, in the ninth game, Alcaraz once again brought out his flair, lashing a backhand passing shot en route to three break points. While Frenchman Rinderknech saved the first, he sent a forehand long on the second and Alcaraz held to wrap up the win.

Lehecka survived a fightback from Mannarino to reach his first US Open quarter-final.

The 23-year-old had one foot in the last eight after winning the first two sets before the unseeded Frenchman hit back, breaking his opponent's serve three times in a 32-minute third set.

Mannarino, 37, also won the first two games of the fourth set, but Lehecka converted the second of two break points to swing momentum back in his favour. He then won the next five games to triumph 7-6 (7-4) 6-4 2-6 6-2.