New York [US], August 20 (ANI): Olympic tennis gold medallist Venus Williams and Reilly Opelka bowed out of the U.S. Open mixed doubles tournament after losing their first round match against Andrey Rublev and Karolina Muchova 4-2, 5-4 at the USTA Billie Jean King National Tennis Center in New York on Tuesday.

The two Americans were broken early, losing their second service game as Williams served. That was the only opening that Muchova and Rublev needed to take the opening set 4-2, as per Olympics.com.

In the second set, it was even through to three games all. Then, Williams stepped up to serve again and got into a sticky situation early, down 15-40. But, urged on by an adoring New York crowd, Williams and Opelka fought off one break point before Williams saved the second with an ace.

The Americans won the game for a 4-3 lead. An easy hold on Muchova's serve pushed the match to a seven-point tiebreak. Rublev and Muchova claimed the second set, taking the tiebreak 7-4, as per Olympics.com.

Williams is making her return to Grand Slam tennis following a two-year hiatus. She made an age-defying singles comeback at the DC Open in July, where she won her opening match against Peyton Stearns, becoming the second-oldest player to win a tour-level singles match. She then lost against Magdalena Frech in the next round.

This week's mixed doubles matches are best-of-three sets up to four games, with no-advantage at deuce resulting in a 'golden point' instead to decide the game. If level at a set apiece, the third set will be in the format of a 10-point match tiebreak.

The mixed doubles final, scheduled for Wednesday (20 August), will take place in the original format of best-of-three sets up to six games, though incorporating the no-advantage rule and super tiebreak up to 10 points. (ANI)