The Serb and the Brit both made huge breakthroughs at the US Open. (Getty)

NEW YORK — Aleksandra Krunic and Johanna Konta faced off in the first round on Monday, both bringing to the court some very fond memories of the US Open. Though Konta, an Australian-turned-Brit, is ranked No. 7 in the world, and Serbia's Krunic is 66 places below her, they have something in common. 

In 2014, Krunic made her presence known in New York by storming through qualifying all the way to the fourth round with upsets over Madison Keys and Petra Kvitova. Many expected her career to take off from there, but she finished the season just outside the Top 100.

"In 2014, I think I was lucky in some things because everything went my way that week," the 24-year-old Krunic told press after her win over Konta. "But before and after that I was not working very hard. I cannot call a fourth round of a Grand Slam 'an accident', that would be stupid. But it definitely wasn't my great work or hard work.

"It was just my talent, my physical abilities that worked together that particular week. The rest of the year and the next year, I wasn't really playing amazing."

In 2015, Konta copied Krunic by battling through qualifying and stunning Garbine Muguruza and Andrea Petkovic to reach the fourth round. Her career actually did take off from there, rising to the Top 50 by year's end and becoming a Top 10 star by the end of 2016. 

With Konta the heavy favorite on Monday, Krunic had to bring her best, which means plenty of variety, fast feet and smart play. She pulled off the 4-6, 6-3, 6-4 upset in 2 hours and 17 minutes. 

"I don't take anything for granted. I think it would be quite obnoxious of me to come in here expecting I have a right to be in second week," Konta said. "The tennis season moves on quickly. We are very spoiled in that sense that we get a lot of opportunity week in and week out to perform and to play."

The disappointment may linger for the 26-year-old Brit, but Krunic can only hope to become as big of a mainstay at the top as Konta has been. 

"I don't think I necessarily played my best tennis today, but my opponent also had something to say about that," Konta said. "She played very freely, I felt, and she moved incredibly well. She made it very tough for me to be able to get any easier points."

Krunic has an opportunity to reach the third round when she takes on Ajla Tomljanovic next.