Seven-time Grand Slam champion Venus Williams returns to the Coupe Rogers in Montreal where she was a runner-up in 2014 losing to Agnieszka Radwanska and she defeated her sister Serena in the semifinals along the way.
The former world number one was a runner-up at the Bank of the West Classic for the sixth time in her career last week, and she lost to Britain's Johanna Konta who knocked her out in the first round of the Australian Open in January.
Madison Keys, the tenth seed reached a career high ranking of 9 in the world last month, but she has fallen to 12 in the world, however, she has an opportunity to get herself back in the top 10 this week depending on how results go.
The younger American has been touted by many to become a future world number one and future Grand Slam champion but Keys suffers too many injuries which may hamper her progress.
How they got here?
Williams as the sixth seed and world number six at the age of 36 is a remarkable achievement for the veteran American who suffers from Sjogren's syndrome.
The runner-up here in 2014 began her quest for her first title in Montreal defeated Barbora Strycova 6-3, 6-0 after receiving a bye in the first round.
Keys playing competitive tennis for the first time since her fourth round exit at Wimbledon to Simona Halep, thrashed Wimbledon semifinalist Elena Vesnina 6-4, 6-0 and she defeated her compatriot Madison Brengle 6-4, 6-3 to set up this encounter with Williams.
Their history
Williams and Keys have played each other three times and the more experienced American leads their head-to-head 2-1.
Their first match was in the quarterfinals of the only green clay court event in Charleston and Williams was victorious 6-4, 6-4 to reach the semifinals.
Keys won their second meeting at the Australian Open in 2015 and it was in the quarterfinals where Keys went on to reach her first Grand Slam semifinal by battling through injury to defeat Williams, 6-3, 4-6, 6-4.
Their most recent meeting was at the WTA Elite Trophy a smaller version of the WTA Finals and Williams was victorious over Keys 3-6, 7-5, 6-1 and went on to win the title.
Williams' Grand Slam record in 2016
Williams reached multiple Grand Slam quarterfinals in 2015 for the first time since 2010 and this year, Williams was ranked inside the top ten but lost in the first round of the Australian Open to surprise semifinalist Johanna Konta.
The veteran American reached the fourth round at Roland Garros for the first time since 2010 which was a good achievement for Williams as clay is her weakest surface and from 2012-2015, Williams suffered first and second round exits at Paris.
The five-time Wimbledon champion entered her 19th Wimbledon campaign and the American had a successful tournament as she reached a Grand Slam semifinal for the first time since 2010 and first at SW19 since she lost to her sister Serena in 2009 in the final.
Williams had a couple of long matches against Maria Sakkari and Daria Kasatkina, however, she ran out of steam in the semifinals against the Australian Open champion Angelique Kerber, but she went on to win her 14th Grand Slam doubles title with her sister Serena at Wimbledon.
Keys' Grand Slam record in 2016
Keys reached the semifinals of the Australian Open in 2015 but she couldn't replicate that performance this year as injury once again hampered the American in her fourth round match with Shuai Zhang and in the final set, Keys could barely move but continued to finish off the match.
For the second consecutive Grand Slam tournament, Keys was ousted in the fourth round by an unseeded opponent and this time it was Kiki Bertens who eliminated Kerber in the first round and went on to reach the semifinals at the French Open.
The American suffered a disappointing three set defeat to Simona Halep at Wimbledon and she appeared to be suffering from injury again.
Who wins?
The veteran American is producing good tennis during the second half of the year and she will be a part of the American contingent going to the Rio Olympics next month.
Williams won singles gold in Sydney back in 2000 and has won three gold medals in the doubles with her sister Serena.
Keys will also be going to Rio and she performs very well on hard courts and she could pose problems for Williams again. The tenth seed will need to serve well and return effectively if Williams is struggling on her serve.
The sixth seed will need to be serving well throughout the match because Keys is usually a good frontrunner but Williams has shown her fighting spirit throughout the summer period.
This match between the Americans should be serve dominated but there could be a few breaks here and there.
All players left in the draw will believe that they can win the Coupe Rogers especially that Williams' younger sister Serena is not competing due to an inflamed shoulder.
The winner of this match will play fourth seed and 2014 champion Agnieszka Radwanska or 16th seed Anastasia Pavlyuchenkova in the quarterfinals.
This match will kick-off the night session on Central and will not start before 6:30pm.
Prediction: Williams in three sets