US Open 2024: Naomi Osaka loses heartbreaker to Karolina Muchova in second round after litany of missed opportunities

Naomi Osaka's return to Arthur Ashe Stadium could have been much different. 

She had seemed to regain some of her swagger in a dominant tournament opener vs. Jelena Ostapenko, and set herself up for success countless times vs. opponent Karolina Muchova in the second round on Wednesday.

But this was ultimately a night defined by missed opportunities for Osaka, who skipped last year's tournament on maternity leave, as she lost in a 6-3, 7-6(5) heartbreaker that saw her spurn a triple-set point and largely fail to capitalize on her crescendos of momentum and crowd support.

'During the pressure moments I got nervous,' a downtrodden Osaka said after the match. 'I don't know if I just have to keep playing more matches and get used to that feeling.' 

This was a match of sliding doors moments for Osaka, who also spurned a 4-2 advantage in a second-set tiebreak and missed a chance for a break point at 2-1 up in the first.

There was frankly one player who held her nerve, and it was not the one most fans paid to see.

Naomi Osaka missed several opportunities to get back into the match vs. Karolina Muchova

Muchova frustrated Osaka all night and wasn't broken until late in the second set - before she would return the favor immediately after

There were glimpses of Osaka's impressive pedigree in this match but that level was ultimately not sustained enough, and the lasting image of the night will be the easy forehand at the net that she missed to lose the match.

Muchova, contrarily, seemed to ratchet up her play as things got tenser and hit perhaps the shot of the night to set up her match point as she fired a cross-court forehand winner in the tiebreak. 

The first breakthrough in the match came for Muchova in the seventh game, as she earned the first break of the night to take a 4-3 lead.

She may have been a faceless competitor to some fans, but the Czech player gave them some moments to savor as well, as a delicate drop shot winner left fans awestruck in that aforementioned game.

There was bite to her game too as she won 5/5 net points in the first set and matched Osaka's power in long rallies as the crowd favorite struggled to get her first serve in early. 

Muchova earned another break up 5-3 to end the set after holding serve, as she slapped a pair of forehand winners past Osaka to seize control of the match. 

Osaka's fortunes looked like they may have been starting to change down 1-0 in the second, when she recovered from a double break point to win the game in a deuce.

Osaka set herself up to play a third set but couldn't close the door on Muchova

The New York supporters, who have twice seen her win this tournament, sensed she needed a boost and got behind her as she won what was essentially a must-win game.

Things remained tight from there until she finally earned a break over the stubborn Muchova, taking a 5-4 lead.

But Osaka gifted her a break right back the next game - from a 40-0 lead no less - as she melted down in the biggest moment of the match to that point. 

From there, Muchova held her nerve in the subsequent tiebreak - and that was really the theme of the match.

Osaka, ultimately, may have struggled at times under Ashe's bright lights on Wednesday - but she was still happy to be back.

'I'm very grateful that there were so many people cheering,' she said. 'I missed it a lot.'