Australia's Olivia Gadecki has continued her strong run of form at the WTA 500 event in Mexico with a straight-sets upset of world number 11 Danielle Collins.

The 22-year-old qualifier dismissed the second-seeded American 6-3 6-3 at the Guadalajara Open and now has a 2-1 career record against top-20 players.

Her previous win over an opponent of that standing came against then-world number four Sofia Kenin back in 2021.

"I'm really proud of myself for giving myself the chance to play another match and play such amazing players and test my abilities," Gadecki said on court.

"I really look forward to continuing."

Gadecki, ranked 152 in the world, converted four of her nine break points and won 68 per cent of second-serve return points against Collins during her 84-minute victory.

The 30-year-old Collins, who is set to retire at the end of the season, made 35 unforced errors, including eight double faults, and has now lost three straight matches since her injury retirement in her Paris Olympics quarter-final against world number one Iga Świątek.

Gadecki, who beat America's Sloane Stephens in the opening round, advances to the quarterfinals, where she will meet Italy's world number 99, Martina Trevisan.

It continues a good run for Gadecki this year, after she secured doubles titles in Austin and Charleston with Brit Olivia Nicholls.

She is currently on a four-match winning streak, her equal second longest of the season and longest at WTA level.

The Gold Coast player defeated Hungarian Timea Babos and Maya Joint in qualifying without dropping a set, before beating former world number three Stephens in the first round.

AAP/ABC