Bianca Andreescu laughed in disbelief at Marta Kostyuk's impressive defensive winner against her at the DC Open.

Former world No. 4 Andreescu faced Australian Open semi-finalist Kostyuk in the opening round of the Citi Open, a combined ATP and WTA 500 event.

Andreescu started the match strongly, winning the first set 6-2. However, Kostyuk fought back well against two break points to ultimately take the second set 6-3.

The most exciting moment came in the final set, where the two women were playing to decide the match. At this point, Andreescu hit a powerful overhead smash at Kostyuk, which most expected would win her the point.

However, the Canadian was left in disbelief after her opponent reacted to the smash instantly, hitting a defense in return that flew back across to Andreescu's side of the court and left the 23-year-old leaning against her racket and laughing at the point she'd just lost.

She wasn't the only one left amazed by the Ukrainian's quick decisions in the moment. In the short clip shared on social media by the WTA, the commentator cries out in astonishment and asks the rhetorical question,

"have you ever seen a defensive shot played like that?!", before calling Kostyuk's shot "the perfect response."

Meanwhile, the WTA page on X, formerly known as Twitter, captioned the video by calling it a "top notch reaction."

Despite the laughter, this point turned out to be crucial for Kostyuk, as the 21-year-old went on to win the final set 7-6 (5). However, the fact that it was so close is a testament to both women's abilities and how well they played on the day.

Kostyuk will go on to face Caroline Garcia in the next round, whilst Andreescu will be preparing to compete in the upcoming Canadian Open.