Il Nuovo Postiglione - Shelton dumped out in Shanghai but Zverev ploughs on

Top seed Alexander Zverev needed three sets against another Frenchman, Quentin Halys, to reach the last 16 and close in on the number one ranking.

The 21-year-old Gea beat the big-serving American Shelton 7-6 (7/5), 7-6 (7/3) for the biggest win of his career.

"I got outplayed today," world number four Shelton told reporters.

"My body wasn't ready," said Shelton, who played at the Davis Cup last month following defeat in the US Open final to Zverev.

Shelton skipped the Japan Open that ended last week due to fitness concerns.

"That's just the way this tour is sometimes," said the 24-year-old, adding that jet lag had also taken a toll.

Gea will play 13th seed Jakub Mensik of the Czech Republic next.

"Amazing, to be honest," Gea said after his first win over a top-10 player.

He added that he has been "more confident on court" following a breakout year that saw him clinch his first ATP title in July in Los Cabos.

He stormed into a 5-3 lead in the first set before Shelton came back fighting, levelling to 5-5 with a clutch backhand volley at the net.

The two players were neck and neck in the tie-break until Gea sneaked ahead to win the first set point.

Third seed Shelton forced his way into another tie-break in the second set as the match went past two hours, but faltered as a charging Gea clinched victory at the first chance.

- Zverev comes through -

Germany's Zverev belatedly saw off Halys 6-4, 6-7 (8/10), 6-3, despite moving a little uncomfortably at the end.

"He plays unbelievably aggressive and serves incredibly," Zverev, himself one of the biggest servers on tour, said of his beaten opponent.

Zverev faces Kazakhstan's 19th seed Alexander Bublik next.

"This year I have been picking my tournaments and places where I want to peak, I did not do that early in my career," said Zverev.

"It paid off, I won two Grand Slams and reached the Wimbledon final."

Zverev cut a frustrated figure at times, barking at his corner even as he clinched the first set against the 48th-ranked Halys in 38 minutes.

The second set was much closer, going with serve and taking them into the tie-break.

Zverev unleashed a delicious backhand down the line to avoid going down 6-4 in the tie-break, but then squandered a match point when he shanked a forehand return.

A second match point came and went, and Halys took full advantage to force a deciding set courtesy of an overhead smash.

The third was poised for another battle, but Zverev broke for 2-0 and behind his reliable serve powered home for victory.

Zverev, the world number two, is an imminent threat to Jannik Sinner's number one ranking.

The US Open and French Open winner has never topped the rankings.

The Italian Sinner is not playing in Shanghai because of injury, opening the door for the 29-year-old Zverev to usurp him.

World number three Carlos Alcaraz is in action in Shanghai on Monday.

The Spaniard faces Belgium's Zizou Bergs in the third round.

O.Nardolillo--INP