After a flawless first set from Mertens the tide turned in Andreescu's direction in the second when she fired a cross-court forehand winner to break the Belgian at love and take a 4-2 lead.
Serena Williams said the latest chapter in her tennis life was "just beginning" on Saturday after seeing her hopes of a record-equalling 24th Grand Slam title dashed in the Wimbledon final.
Prajnesh Gunneswaran got a taste of high-level tennis in his first-round exit from the US Open, losing to world number five Daniil Medvedev in 84 minutes, in New York, on Monday.
The US Open reached an emotional climax on Sunday as the year's final grand slam paused amid heavy security before the start of the men's singles to remember those who died in the 9/11 attacks 15 years ago.
Serena Williams will be wary of another semi-final slip-up when she takes to the Arthur Ashe Stadium court on Thursday to face 10th seed Karolina Pliskova for a spot in the US Open final.
The 24-year-old started brightly by taking the first set off the 19th seed on Monday but his lack of match fitness told as, despite frequent treatment from the trainer, he lost the next three to bow out at the first hurdle in a third straight grand slam.
Fritz delivers as US win inaugural United Cup crown
Venus Williams became one of the oldest players to win a WTA title when she beat Caroline Wozniacki in the final of the Auckland Classic on Saturday.
Here are some of the reactions to the Grand Slam - originally scheduled for June 29-July 12 - being cancelled for the first time in 75 years.
Tennis great and founder of the WTA Billie Jean King was among those who applauded the announcement.
Serena Williams, who held all four of tennis's grand slam titles for the second time in her career and won 53 of 56 matches in 2015, was named Sportsperson of the Year by Sports Illustrated magazine on Monday.
Naomi Osaka ended Victoria Azarenka's dream run to claim her second US Open title in three years with a 1-6, 6-3, 6-3 comeback win on Saturday which cemented her status as the sport's leading light both on and off the court.
IMAGES from Day 8 of the action at the US Open at USTA Billie Jean King National Tennis Center at Flushing Meadows in New York on Monday.
IMAGES from matches on Day 4 of the US Open at Flushing Meadows in New York on Thursday.
World No 1 Novak Djokovic beat Roger Federer 6-4, 5-7, 6-4, 6-4 to win the US Open title at the Flushing Meadows in New York on Sunday.
Rediff.com presents the early surprises at the year's final Grand Slam
'He probably deserves a player that is probably more dedicated to the game than I am. He deserves a better athlete than me'
However, the 30-year-old Russia belied her own self-doubt with an impressive three-set win over the Romanian to thrust the former world number one back into the spotlight as the toast of the Big Apple.
More stars than they are in heaven were at the Sachin: A Billion Dreams premiere.
Leylah Fernandez's storybook US Open continued with yet another upset on Thursday, as the Canadian teenager shocked second seed Aryna Sabalenka 7-6(3), 4-6, 6-4 to reach her first Grand Slam final.
Zhang Shuai stunned Wimbledon Champion Angelique Kerber 6-1, 2-6, 6-0 in the China Open on Thursday to set up a quarter-final clash with Naomi Osaka.
Images from Day 1 of the 2022 US Open at the USTA Billie Jean King National Tennis Center, in Flushing Meadows, New York, on Monday.
Tennis star Maria Sharapova said on Tuesday she is excited about her return to competition next month, feeling vindicated by the reduction of her doping suspension and empowered by her time away.
BNP Paribas Open chief executive and tournament director Raymond Moore provoked outrage with controversial comments he made before the women's and men's finals at Indian Wells, and later issued an official apology.
Long before Simona Halep's demolition job on Serena Williams at the WTA Finals, the Romanian was already winning over another of the game's greats.
The Year of the Rabbit, according to the Chinese calendar, began on Sunday, January 22.
Legendary Sachin Tendulkar has revealed that the first thoughts of retiring from international cricket came to his mind in October 2013 during a Champions League T20 match in New Delhi, just a month before he decided to call it quits.
IMAGES from Day 9 of the US Open matches played on Tuesday
Roger Federer called on Wednesday for a merger between the men's ATP Tour and the WTA, which runs the women's circuit, as tennis wades through a lengthy coronavirus shutdown with lower-level professionals in deep financial crisis. The tennis season was suspended in March due to the COVID-19 pandemic and the hiatus will continue at least until mid-July, depriving lower-level players, who depend solely on tournament winnings, of the chance to earn a living.
The organisers of the US Open said on Thursday a decision on whether to hold the Grand Slam this year amid the coronavirus outbreak will be made in June, and playing it without fans is on the table but highly unlikely. The US Open, which is scheduled to run from August 31 to September 13, is both the largest and loudest of the four Grand Slam events on the tennis calendar and United States Tennis Association (USTA) chief executive Mike Dowse does not anticipate that changing.
Angelique Kerber showed more passion in the media centre than on the court when she crashed out of last year's WTA Finals, the German angered by the format and frustrated by her inability to win the set off an eliminated opponent she needed to advance.
IMAGES from Day 6 of the 2023 US Open on Saturday.
IMAGES from Day 5 of the US Open, at the USTA Billie Jean King National Tennis Center, Flushing Meadows, New York, on Friday.
Germany's second seeded Angelique Kerber beat Czech Karolina Pliskova 6-3, 4-6, 6-4 to win the US Open final on Saturday, and collect her second Grand Slam title of the year.
Andy Murray said on Thursday the noise created by the US Open's new retractable roof over Arthur Ashe Stadium is a distraction to players and makes it difficult to react to opponents' shots.
Eugenie Bouchard slumped to a first-round defeat at the US Open on Tuesday but the Canadian might yet leave Flushing Meadows a big winner with her lawsuit against the Grand Slam and United States Tennis Association still to hit the courts.
The United States has named former tennis star Billie Jean King, one of the first prominent athletes to publicly acknowledge her homosexuality, to be in the U.S. delegation to the Winter Olympics in Sochi, where Russia's anti-gay policies have stirred controversy.
Recently-elected FIFA president Gianni Infantino was told on Monday that 'women are part of the solution' to the problems that have plagued football's scandal-plagued world governing body.
Roger Federer launched his bid for an 18th grand slam title with a workmanlike 6-3, 6-4, 7-6 (4) win over Marinko Matosevic to ease into the second round of the US Open on Tuesday, with NBA great Michael Jordan leading the cheering.
Images from Day 2 at the US Open played at Flushing Meadows in New York on Tuesday
