LIU, KLAHN WIN ON EXCITING WIMBLEDON DAY 2

If Day 1 of Wimbledon was about the American seeds advancing, the second day was about a pair of feel-good stories featuring lesser-heralded members of Team USA.

Reigning girls' junior champion Claire Liu (pictured above) won her main-draw debut, and 27-year-old Bradley Klahn picked up his first Grand Slam singles victory in five years in the English capital Tuesday.

Liu, who was awarded a wild card into last week's qualifying tournament, found success in her first return to London since winning the girls' title 12 months ago, beating fellow teen Ana Konjuh of Croatia, 6-2, 6-7, 6-3.

It was an impressive win for the 18-year-old, ranked No. 237 in the world, who will now face 2016 US Open champion and No. 11 seed Angelique Kerber on Thursday.

As for Klahn, who defeated Yuichi Sugita, 2-6, 7-6, 6-2, 6-2, the first Wimbledon win was the same, but the path he took was very different.

A Stanford University alum, Klahn reached as high as No. 63 in the rankings in March 2014 before undergoing back surgery twice in 2015, during which time he contemplated retirement and life after tennis.  

But playing in his first major singles main draw since the 2014 US Open, Klahn showed he's not content to sit on the sidelines. His reward for a first-round win over Sugita is a date with top-ranked Brit and No. 21 seed Kyle Edmund in a match that will likely get the show-court treatment on Day 4.

After going 9-7 on Day 1, Americans went 9-6 on Day 2, giving the U.S. 18 players in the second round, more than any other nation had before the tournament started.

Elsewhere on Day 2, Taylor Fritz defeated qualifier Lorenzo Sonego, 3-6, 6-3, 6-2, 6-2, in a little over two hours on Court 7 to set up a second-round match against No. 4 seed Alexander Zverev, and Frances Tiafoe upset No. 30 seed Fernando Verdasco, 7-6, 7-6, 3-6, 6-3.

For Tiafoe, the win gets a proverbial monkey off his back. This is the fourth consecutive major that unseeded Tiafoe has drawn a seed in the opening round. But unlike in New York, where he lost to Roger Federer in a five-set instant classic, in Melbourne, where he fell to former Grand Slam champ Juan Martin del Potro, and in Paris last month, where he feel to countryman Sam Querrey, Tiafoe was able to advance.

Tiafoe will play Julien Benneteau for a spot in the third round and, with No. 7 seed Dominic Thiem out, the draw has suddenly opened up for the 20-year-old competing in his second Wimbledon main draw.

Also winning Tuesday was 23-year-old Florida resident Jennifer Brady, who defeated world No. 67 Kateryna Kozlova, 6-2, 6-7, 6-2, on Court 6, and 22-year-old Taylor Townsend, who defeated France's Pauline Parmentier, 6-2, 6-4, to move into the second round of Wimbledon for the first time in her career.

Brady, ranked No. 74, will play Anett Kontaveit, the No. 28 seed, in round two, while Townsend will play world No. 50 Aliaksandra Sasnovich, who upset pre-tournament favorite and No. 8 seed Petra Kvitova.

Joining Brady and Townsend in the round of 64 is Alison Riske, the world No. 60, who needed just 57 minutes to beat Mariana Duque-Marina of Colombia, 6-1, 6-1;  19-year-old Sofia Kenin, who beat 22-year-old world No. 37 Maria Sakkari of Greece, 6-4, 1-6, 6-1; and Sachia Vickery, who dropped just three games in beating Marketa Vondrousova of the Czech Republic.

Riske, who celebrated her 28th birthday Tuesday, has points to defend in London after she reached the third round last year, but it doesn't get any easier in round two, where she'll meet Belinda Bencic, who upset No. 6 seed Caroline Garcia.

Kenin, meanwhile, could next face Maria Sharapova in a rematch of their US Open third-round battle from September, while Vickery gets 15th-seeded Elise Mertens of Belgium.

However, Caroline Dolehide fell to No. 26 seed Daria Gavrilova of Australia, 6-2, 6-3, and Danielle Collins lost to Mertens, 6-3, 6-2.

In the men's draw, qualifier Christian Harrison lost to 24th-seeded Kei Nishikori, 6-2, 4-6, 7-6, 6-2; Tenny Sandgren fell in straight sets to No. 12 seed and former Wimbledon champ Novak Djokovic; and Jack Sock's inconsistent first half of 2018 continued with a five-set loss to Matteo Berrettini after the American had a two-set lead.

In a match carried over from Day 1, Christina McHale fell to Vera Lapko of Belarus, 5-7, 7-5, 7-5.