In this task, you are given an article. Your task is to summarize the article in a sentence.
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Question: Top seed Murray, 30, is trying to reach the last eight in Paris for the sixth time in the past seven years.
Khachanov, 21, is ranked 53rd and plays his first Grand Slam last-16 match after beating American John Isner.
"Mentally I feel pretty good just now," Briton Murray said after beating Juan Martin del Potro in round three.
Having struggled with fitness and form during much of the year, the Scot played superbly to see off the Argentine in straight sets on Saturday.
"After each round, I'm not thinking about winning," he said.
"I didn't come here with the mindset that I'm definitely going to go a long way.
"I was going to try and just get through the first round and hopefully feel better each day. That's been the case so far."
Khachanov poses a new challenge for the Wimbledon champion, and it will be the Russian's first match against any of the very top names in the sport.
He said: "That is what we are looking for, to play on the big arenas like here, centre court, and to play against world number one. I'm really looking forward for it."
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Khachanov was born in Moscow but has trained in Barcelona for the past three years, during which time he has risen from outside the world's top 400 to become a fixture around the top 50.
The 6ft 6in right-hander has plenty of power, as he showed in seeing off big-serving Isner in the third round.
That followed his best win to date over 13th seed Tomas Berdych.
"I practised with him before he got on to the tour when he was like 350, and he was really good," said Murray.
"Big, strong guy. Generates a lot of power. He's also got a big serve."
Khachanov has hit 29 aces to Murray's 16 in the tournament, and has spent an hour less on court at just under the eight-hour mark.
Murray will head into the match with a very different mindset, however, following his impressive performance against Del Potro.
"I believe in myself, so even when things aren't going well, I believe I can turn it around," said Murray.
"The five-set format has definitely helped that, so I have maybe not been as anxious going into some of the matches, because I know there is some time to turn it around."

Answer: World number one Andy Murray will face up-and-coming Russian Karen Khachanov in the fourth round of the French Open at about 11:30 BST on Monday.


Question: The fee will also apply to UK-based lorries - but this will be offset by an equivalent cut in vehicle excise duty.
The move is designed to create a "level playing field" for British lorry drivers, as they have to pay for using roads in Europe.
The AA said it was concerned the system could lead to a universal road charging scheme for all motorists.
The government will publish draft legislation next month and ministers said the charge would be brought in by the end of the current parliament at the latest.
The amount of the charge would depend on the size of the vehicle and is expected to raise a total of £20m a year.
Transport Secretary Patrick McLoughlin said: "These proposals will deliver a vital shot in the arm to the UK haulage industry.
"It is simply not right that foreign lorries do not pay to use our roads, when our trucks invariably have to fork out when travelling to the continent.
"By introducing charges we will create a level playing field, increasing UK competitiveness and boosting growth."
British hauliers who operate in Europe face a variety of road tolls and charges while continental lorries can use British roads for free.
Road Haulage Association chief executive Geoff Dunning said it was a "happy day" for the industry.
"We have been campaigning for years to see a system introduced which will lessen the financial advantage currently enjoyed by our European neighbours," he said.
"UK hauliers travelling to mainland Europe have to pay road charges but foreign-registered vehicles travelling to the UK pay nothing."

Answer: Foreign lorries are to be charged up to £1,000 a year to use British roads - in a bid to benefit domestic hauliers.


Question: Brain scans showed that they are the areas associated with complex thought processes.
The scientists also discovered a link between teenage brain development and mental illness, such as schizophrenia.
The research is published in the Proceedings of the National Academy of Science.
The team from Cambridge's department of psychiatry scanned the brains of 300 people between the ages of 14 and 24.
While the areas associated with the basic functioning of the body such as vision, hearing and movement are fully developed by adolescence, the areas associated with complex thought and decision making are still changing.
These areas are nerve centres with lots of connections to and from other key areas.
You can think of the brain as a global airline network that's made up of small infrequently used airports and huge hubs like Heathrow where there is very high traffic.
The brain uses a similar set up to co-ordinate our thoughts and actions.
During adolescence, this network of big hubs is consolidated and strengthened. It's a bit like how Heathrow or JFK have become gradually busier over the years.
How schizophrenia changed the course of my life
Why brains are beautiful
The researchers then looked at the genes involved in the development of these brain "hubs" and found that they were similar to those associated with many mental illnesses, including schizophrenia.
The discovery is in line with the observation that many mental disorders develop during adolescence, according to researcher Dr Kirstie Whitaker.
"We have shown a pathway from the biology of cells in the area through to how people who are in their late teenage years might then have their first episode of psychosis," she told the BBC.
Many studies have shown that, in addition to genetics, stress during childhood and the teenage years is linked to mental illness.
The new findings indicate that maltreatment, abuse and neglect may well continue to disrupt the development of the higher brain functions during the crucial teenage years and so contribute to the emergence of mental illness.
Symptoms of schizophrenia:
Lead researcher Prof Ed Bullmore, whose work was funded by the Wellcome Trust, believes the discovery of a biological link between teenage brain development and the onset of mental illness might help researchers identify those most at risk of becoming ill.
"As we understand more about what puts people at risk for schizophrenia, that gives us an opportunity to try to identify individuals that are at risk of becoming schizophrenic in the forseeable future, the next two to three years, and perhaps to offer some treatment then that could be helpful in preventing the onset of clinical symptoms. "
The study also sheds light on the mood and behavioural changes experienced by teenagers during normal brain development.
"The regions that are changing most are those associated with complex behaviour and decision making," says Dr Whitaker.
"It shows that teenagers are on a journey of becoming an adult and becoming someone who is able to pull together all these bits of information.
"This is a really important stage to go through. You wouldn't want to be a child all your life.
"This is a powerful and important stage that you have to go through to be the best and the most capable adult that you can be."

Answer:
A University of Cambridge team has identified the areas of the brain that change the most during the teenage years.


