Around the time Federer was warming up for his match with the 45th-ranked Russian, Andy Murray announced he was pulling out of the Brisbane International, while Novak Djokovic a few days earlier withdrew from his season opener in Abu Dhabi.
Rafael Nadal, Stan Wawrinka, Milos Raonic and Kei Nishikori are also under injury clouds, while world number eight Jack Sock succumbed to a hip problem earlier in the day in Perth, forcing him to retire from his singles match.
The 36-year-old was too good for Khachanov, making it two straight-sets wins from as many singles matches this week as Switzerland beat Russia 3-0 in their Group B tie in front of a record Hopman Cup crowd.
Federer was stretched by Khachanov, particularly in the second set when the pair traded powerful groundstrokes.
The Russian held a set point in the tie-breaker and also saved two match points held by Federer, before the Swiss champion prevailed after Khachanov hit a forehand perilously close to the line.
"I thought the intensity was great and the level high too," Federer said.
"It was a good match overall and I was happy with my performance."
The 74-ranked Belinda Bencic, on the comeback trail after injuries stalled her promising career, then upset world number 15 Anastasia Pavlyuchenkova in three sets, 6-1, 3-6, 6-3 in just under two hours to clinch the tie for the Swiss.
In the dead mixed doubles rubber, the Swiss completed a clean sweep with a three-set win under the Fast4 format.
=====================
Both Switzerland and the United States' pairing of Sock and CoCo Vandeweghe, who beat Japan 2-1 in contentious circumstances earlier in the day, have won their opening two ties.
The victor in their clash on Thursday will advance to Saturday's final and Federer said he expected Sock to be fit for that tie.
Sock retired early in the second set of his men's singles clash with Japan's Yuichi Sugita, having injured his hip during a first set tie-breaker.
The Group B tie ended with an exhibition mixed doubles match featuring the return of 52-year-old former Wimbledon champion Pat Cash to the court to team with Vanderweghe, who he coaches.
Prior to Sock's injury, Japan's Naomi Osaka had withdrawn from her singles match with Vandeweghe due to illness.
The end result of the injury and illness for both sides was the United States being given an intriguing 2-1 win, as Japan was ruled to have forfeited the women's singles and mixed doubles before the Sock injury.
However, the fitness of Sock for the remainder of the tournament, and more importantly the upcoming Australian Open, was in doubt after he limped off the court.
Vandeweghe and Sock were beaten by the French team of Kristina Mladenovic and Richard Gasquet in last year's decider.
Disclaimer: No Business Standard Journalist was involved in creation of this content
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
