NEW YORK – It is just the second day of the US Open but we already have quite a few fascinating storylines under our belt. On Tuesday, for instance, there was a huge upset on the men's side as world No. 12 David Goffin of Belgium was ousted by 19-year-old Jared Donaldson of the United States.

For Donaldson, a native of Providence, Rhode Island, the third time is the charm as he failed to get past the opening round in each of the last two years at Flushing Meadows. He broke through this time, though, defeating Goffin 4-6, 7-5, 6-4, 6-0 to advance to the second round.

While Goffin slightly led in the unforced errors column by a 56-54 margin, Donaldson convincingly led the way with 12 aces to the Belgian's one and committed just five double faults to Goffin's 17. But while the match was fairly close in the opening three sets, Donaldson dominated the decisive set, closing out the match with a backhand unforced error to take the set 6-0.

For Goffin, this was not the way he wanted to close out the grand slam season.

In what has been a promising 2016, the 25-year-old Belgian reached the fourth round at the Australian Open and Wimbledon, the quarterfinals at the French Open and his first-career semifinal berth in a Masters 1000 series. Unfortunately, after consecutive third-round showings at the US Open, Goffin will be going home earlier than he had anticipated.

This was the first-ever meeting between Donaldson and Goffin and the younger American made the most of it. But the road doesn't get any easier in New York this week as waiting in the second round will be world No. 32 Viktor Troicki of Serbia.

To get to the second round, Troicki played catch-up against Radu Albot of Moldova, going the distance before ultimately defeating him 5-7, 3-6, 6-4, 6-4, 7-6(7).

Donaldson and Troicki, who had never faced each other, will battle it out on Wednesday.

On the women's side, there was another first-time matchup as Ukraine's Kateryna Kozlova squared off with the grizzled veteran in Venus Williams.

Despite being ranked No. 6 in the world, Venus is considered to be a dark horse in this tournament.

A holder of 49 career singles titles, Williams has won seven grand slams including two US Open crowns in consecutive years. However, Venus has not won a US Open title since 2001 when she defeated sister Serena in the final.

On Tuesday, Venus was hoping to get off on the right foot in the Big Apple, and she did by taking the opening set 6-2. But Kozlova, who was just eight months old when Williams turned pro in 1994, battled back by winning a marathon second set 7-5 to set the stage for a third and deciding set.

In the deciding set, it was another battle but the veteran pulled away as Venus defeated Kozlova 6-4 to take the set and the match. It was fairly even all the way but Venus's 46 winners to Kozlova's 21 is what separated the two as the American advances to the second round to face Julia Goerges of Germany.

Ranked No. 64 in the world, Goerges has faced Venus just once, losing to the American 6-3, 6-2 at the 2015 Wuhan Open in China. The German, though, had an easier time in her first-round match, defeating Belgium's Yanina Wickmayer 6-3, 6-2.