The two top seeds failed to get out of the gate at the Abierto GNP Seguros in Monterrey on Tuesday, while Harriet Dart won the Battle of the Brits, beating Heather Watson in two tight sets in the first round in Mexico.
Dart, who is ranked No 3 in the British rankings, a place lower than Watson, won the contest, 6-4 7-6(1), after an hour 39 minutes.
She was beaten in the 2nd round of qualifying but made it into the main draw as a lucky loser after Danka Kovinic pulled out through injury, while Watson, 28, was seeded No 5.
On Tuesday, Dart got off to the brighter start with an immediate break of Watson’s serve, but was soon pegged back as the British No 2 reeled off 3 games in a row.
Dart steadied herself and broke Watson again, this time consolidating by holding onto her advantage to wrap up the first set.
Watson came back strongly at the start of the second, quickly coming back at Dart from an immediate break again at the start and, once more winning the next 3 games on the trot.
Dart rallied to break Watson as she served for the second set, and then got things back on an even keel, pushing the contest into a tiebreak in which she ran away with the match with the loss of just 1 point.
Dart, 24, who is the World No 153, seal her first win over the more experienced Brit and will now play Viktoria Kuzmova in round two after the Slovakian World No 104 beat American wildcard Caroline Dolehide 6-3 6-1 in round one.
Although their most recent meeting was in Fed Cup in 2020, Dart comes into this match a lot sharper having had much more court time than Kuzmova, who picked up her first win of the season over the American.
Dart will be riding high with a win over Watson, and should have a bit of a spring in her step when she takes on the Slovak.
Crashing out, of the draw however, were top seeds Sloane Stephens and Nadia Podoroska, who lost to Kristina Kucova, the Slovakian lucky loser, and Russia’s Anna Kalinskaya, a qualifier, respectively.
Kucova ousted American Stephens in straight sets 6-2 6-2 in merely 70 minutes, while at the bottom of the draw, Kalinskaya took down Argentina’s Podoroska, 6-4 6-4 in an hour and 34 minutes.
In the second round, Kucova will play Canadian teenager Leylah Fernandez, a first round winner on Monday, while Kalinskaya takes on Nina Stojanovic, from Serbia, who scored a 6-3 6-3 win over Italy’s Martina Trevisan on Tuesday.
Swiss qualifier Viktorija Golubic also posted an upset, over 6th seed Anna Blinkova from Russia in the first round in straight sets, 6-4 6-4, in an hour and 52 minutes.
Golubic will play against America’s Lauren Davis in round 2.
The only 2 seeds to advance safely into the round of 16 were 3rd seed Saisai Zheng from China and 7th seed Sara Sorribes Tormo from Spain.
Zheng defeated Russian Varvara Gracheva, 6-3 7-5, in an hour and 37 minutes and will next play compatriot Lin Zhu, who defeated Canada’s Eugenie Bouchard.
The Canadian reached the final of the Guadalajara Open last week but went down to Gracheva, 7-5 7-6(3) in the last match of the day.
The Spaniard, meanwhile, came from a set down to beat Ukrainian Lesia Tsurenko, 5-7 6-2 6-4, in a marathon that was only 7 minutes shy of 3 hours.
The match featured 16 breaks of serve, but the Spaniard, who won her first WTA career title last week at the Guadalajara Open and has reached a career-high of No 57 in the rankings this week, was convincingly able to outlast Tsurenko.
In the second round at the Monterrey Open, Sorribes Tormo will play Slovenia’s Kaja Juvan, who won the qualifiers’ derby against Maria Camila Osorio Serrano from Spain, 6-4 6-4.