Van de Zandschulp got off to a torrid start in Shanghai, losing five games on the trot after winning fewer than half of his service points and just 6 of 22 return points, handing Merida a first-set win in just 23 minutes.

The 41st-ranked Dutchman upped the ante in the second set, breaking his Spanish opponent twice in a row to grab a quick 4-1 lead with aggressive net play. A rapidly improving Van de Zandschulp took the set 6-3 before continuing his dominant showing in the final set, racing to a 4-0 lead.

Merida wasn't ready to submit just yet and clawed his way back with a re-break, but ultimately couldn't stop Van de Zandschulp from reaching the second round of the Shanghai Masters for the third time in four years with a 6-4 win. 

Up next for Van de Zandschulp is 31st seed Alex Michelsen.

Griekspoor continues Asian downfall

Earlier on Thursday, former Dutch No. 1 Tallon Griekspoor continued his losing streak in Asia by falling to qualifier Pavel Kotov in straight sets: 6-4, 7-6 (4).

Griekspoor was handed a seemingly favourable draw by facing a qualifier in the opening round, but started dreadfully on the returns as he tallied just 2/22 return points en route to a painful 6-4 set loss.

Kotov, who eliminated Martin Damm and Aleksandar Vukic in Shanghai qualifiers, kept the upper hand in the second set and started with his next break, but saw Griekspoor take a step up after the Dutchman fended off two break points and forced a tiebreak in a hard-fought set.

It was all to play for as Griekspoor and Kotov exchanged two break points apiece, but the Dutchman did not have enough in him to keep the Russian from winning as his 16 unforced errors in the second set led to another first-round defeat - his third in a row to start the Asian swing.