Robin Montgomery was a week old the last time a girl won both the singles and doubles titles at the US Open Junior Championships in Flushing Meadows New York.

When Michaela Krajicek of the Netherlands claimed both titles in 2004, Montgomery was six years away from picking up a racquet for the first time. Now her junior career is complete, after defeating Kristina Dmitruk of Belarus 6-2 6-4 in the singles final and partnering with Ashlyn Krueger to take the doubles title in an all-US final Saturday.

"I was just trying to make it past the second round," the 17-year-old left-hander from Washington DC said of her expectations coming into the tournament. "I didn't picture myself making the finals, but I wanted to do well because it's my last slam."

Dmitruk started quickly, showing no sign of nerves, but Montgomery was able to take control in the sixth game of the first set, breaking Dmitruk at love for a 4-2 lead and finishing it with another break.

The second set didn't start well for the American, when she was broken at the start, more due to her own errors than Dmitruk's improved play.

"I was a little bit worried to be honest, when she broke me that fast," said Montgomery, the No. 7 seed. "Then she went up 2-0 and that's when I got a little bit more nervous. My goal then was not to lose the set 6-0, to focus on just getting a game."

Dmitruk held on her break for 4-2, but as in the first set, Montgomery began to dig in. She pulled even at 4-4, saved a break point with a brave backhand winner before holding for 5-4, and was able to keep her mind on the task at hand in the final game.

"I noticed my thoughts were going a little bit crazy at 4-all," Montgomery said. "I was a bit more nervous because I had already played such good tennis over those games, and I was nervous she was going to step it up."

That didn't happen, as Montgomery relied on her return game again, ending her second four-game run of the match with another break, this one for the title.

Dmitruk, getting her first look at Montgomery's game, recognized it as well-suited for the fast hard courts of the USTA Billie Jean King National Tennis Center.

"She played very aggressive," said the sixth-seeded Dmitruk, who turns 18 in two weeks. "For hard, it's very good, it's what you should do. She played much harder than me, and she has a good serve, so it's play aggressive, go into the court."

Montgomery was the crowd favourite, and she appreciated their support, yet having her family and her longtime coach Ali Agnamba of the Junior Tennis Champions Center in New York to witness her two titles was especially gratifying.

"My family that lives in New York came to watch me, my mom, grandma and aunt came up from DC, and I love playing in front of all them," Montgomery said. "The last time my grandma saw me play was Orange Bowl, when I won that, so I was really happy I could pull out another tournament in front of her eyes."

As for her coach, Montgomery considers him family too.

"He's been with me since I was six," Montgomery said. "He's like family to me. I didn't grow up with a father, it's always been my mom and grandma raising me pretty much. Since I met him so young, he kind of became a father figure to me...he just means so much to me. Tomorrow is actually his birthday, so I told him this is his birthday present."

The second early birthday gift Agnamba received came in the doubles final, with No. 3 seeds Montgomery and Krueger defeating No. 8 seeds Reese Brantmeier and Elvina Kalieva 5-7, 6-3, 10-4. Montgomery and Krueger won the National 18s title last month, earning a wild card into the women's doubles two weeks ago, and they defeated No. 13 seeds Asia Muhammad and Jessica Pegula 6-2 7-6(5) in the first round. After that win, and saving two match points in their quarterfinal match this week, Krueger and Montgomery were not surprised by their continued success.

"We go into every match thinking we have a chance and we know on our good days we can compete with anyone," Krueger said.

The boys final between No. 3 seed Daniel Rincon of Spain and top seed Juncheng Shang of China entertained the large crowd that gathered around Court 12 prior to the women's singles final on Ashe, with Rincon winning a pivotal game late in the second set that led to his 6-2 7-6(6) victory.

Rincon was the steadier of the two left-handers in the first set, but Shang brought a higher level of play to the second set, serving for it at 5-4. He had four set points in the game, with both bad luck (a net cord winner for Rincon) and nerves (a double fault) sending the score to deuce. Finally, another double fault cost Shang the game.

Rincon said the key to battling through that game was concentrating on each point.

"If you think about the big picture, it gets hard to win matches like that," said the 18-year-old, who trains at the Rafael Nadal Academy and has often practiced with the Spanish legend. "So I just try to focus point by point. I just said to myself, look, make him play every point, and if he wins every point with a winner, good job, we'll have a third set. But that wasn't the case and I'm really happy I got through to win that game."

Shang knew he had let a golden opportunity slip away.

"I think that game was obviously the most important game of the match," Shang said. "If I had won that game, the third set would have been a different story. But I think I was rushing a little bit and I was looking for the winners instead of being patient on every ball. I kind of threw it away. I had a lot of chances, and that was just a little mental breakdown. I just was giving it away. He didn't play that well."

In the tiebreaker, Shang went up 5-2, but Rincon's two excellent first serves narrowed the gap to 5-4, and another net cord in his favour brought it to 5-all. Shang saved one match point with Rincon serving at 6-5, but another good first serve gave Rincon a second, and he manoeuvred to get himself a short forehand. The powerful result was close to the line, and Rincon didn't hear any out call, but with the recorded automated line call used in this tournament not always audible above the crowd noise, he couldn't be certain he had won the match.

"It was a combination," Rincon said of his reaction, which was both hesitant and stunned. "I didn't know if it was in or out and I couldn't believe that I had won the match. So, I just waited for the ref to say game, set and match and went on the floor and enjoyed the moment."

The boys’ doubles title went to the unseeded team of Max Westphal of France and Coleman Wong of Hong Kong, who defeated No. 8 seeds Viacheslav Bielinskyi of Ukraine and Petr Nesterov of Bulgaria 6-3 5-7 [10-1]. Wong did not get through qualifying in singles, so he was not sure he and Westphal would get into the doubles tournament, but once they did, and beat the Wimbledon champions in the first round, they were on their way.

All five of Westphal and Wong's victories came via third-set match tiebreakers.

"All the time we played unbelievable for the third set," said Westphal, who is beginning his collegiate career this month at Columbia University in New York. "I think it was the body language, the way we were acting in the third sets made us win, nothing else."

"It's amazing," the 17-year-old Wong said. "When I lost in singles qualies I was a bit down and I don't know if I'm going to make it into doubles. We had the toughest draw, but after that first match we played much better, and this is it."