NEW YORK, NY, USA -- Playing together for the first time, American wild cards Christina McHale and Christian Harrison are making the most of their debut event, reaching the US Open semifinals in mixed doubles on Tuesday with a 6-3, 6-4 win over No.5 seeds Andrea Sestini Hlavackova of the Czech Republic and Edouard Roger-Vasselin of France.

"It’s been really exciting," a thrilled McHale told the media, after her team's quarterfinal victory. "I think from the first match, we’ve had a tough draw, but with each match, we’re feeling more comfortable playing together, and we’re just having fun out there."

"Christian has a great serve and a great sense up at the net, and I think my groundstrokes kind of set him up, so I think that is a good combination," McHale explained, as the key to their success. "I think we’re just really enjoying being out on court, and this is our home Slam, and singles didn’t go so well for both of us, so it’s just so nice to get some wins in doubles. We just want to keep sticking around."

Despite this being their first mixed event together, McHale and Harrison have had a strong connection for some time — McHale's older sister Lauren is married to Harrison's older brother Ryan. "We obviously know each other well, being family and everything, and we’re just having a really good time," said McHale, who was the only player not to drop serve in the match.

The match started inauspiciously for the Americans, as Harrison dropped serve in the opening game after firing a forehand into the back of his partner in the forecourt on break point. But the misstep was quickly rectified as Roger-Vasselin dropped his own serve in the very next game to level the match at 1-1.

The American tandem then obtained the pivotal break of the first set, as McHale slammed an stunning overhead winner on deciding point to take Sestini Hlavackova's serve and lead 5-3. The powerful Harrison then held serve in a tense game to open up a one-set lead.

The teams exchanged breaks early in the second set en route to a deadlock at 4-4. In that game, Roger-Vasselin dropped serve once more after an excellent McHale backhand forced a Sestini Hlavackova volley wide on deciding point. At 5-4, Harrison was again tasked with closing out the set, and he was up to the challenge once more, using his power game to seal the straight-set victory.

There is no rest for McHale and Harrison, as tomorrow they will face a team of two former World No.1 doubles players, Bethanie Mattek-Sands of the United States and Jamie Murray of Great Britain.

"Every time we win, I check the draw, and it just keeps getting tougher!" McHale exclaimed. "It’s going to be a lot of fun. Bethanie’s a good friend. We’re into the semifinals of a Slam, this is a new feeling for Christian and I, so we’re just going to enjoy as much as we can."

The mixed doubles semifinals were finalized on Tuesday as Poland's Alicja Rosolska and Croatia's Nikola Mektic defeated Romania's Raluca Olaru and Croatia's Franko Skugor, 7-6(5), 6-4. Rosolska and Mektic will meet Zhang Shuai of China and John Peers of Australia in the final four.