From Andy Murray vs Juan Martin del Potro Olympics rematch to Rafael Nadal missing out in Delhi, here's a look at all the Davis Cup action on Friday.
Spain vs India
Spain took a commanding 2-0 lead over India in the Davis Cup World Group playoff despite the last-minute pullout of star player Rafael Nadal in New Delhi on Friday.
Feliciano Lopez, who took court in place of Nadal in the first match, and David Ferrer claimed contrasting victories in their respective singles matches.
The left-handed Lopez served past Ramkumar Ramanathan 6-4, 6-4, 3-6, 6-1 while the 13th-ranked Ferrer outplayed Saketh Myneni 6-1, 6-2, 6-1.
In the first match, Lopez broke in the fifth game to go 3-2 up in the first set, setting the pace against an opponent who played his heart out in front of a raucous home crowd.
The 34-year-old Lopez kept the momentum going in the second set with his excellent range of shots, seemingly unfazed by the hot and humid conditions.
The 21-year-old Ramanathan, placed 203rd in the ATP rankings, broke Lopez in the eighth game of the third set to pull one back and get the home fans behind him.
But Lopez soon gained ground and showcased his superiority in the final set of the match.
Ferrer came out all guns blazing in the second match of the day to take the first set in just 21 minutes and unsettle India's Myneni, who is ranked 137th.
The 2013 French Open finalist was broken just once in the sixth game of the second set to stamp his class on the match.
Ferrer, who stunned Myneni with his speed and baseline play, kept up the pace through the course of the match to wrap up things in just one hour and 28 minutes.
Spain will stay in the premier World Group next year if they win one further match in the best-of-five rubber.
Great Britain vs Argentina
Argentina was in sight of a first Davis Cup final since 2011 after taking a 2-0 lead over titleholder Britain thanks to singles wins by Juan Martin del Potro and Guido Pella in the semifinal on Friday.
Del Potro ended Andy Murray's 14-match winning streak in the Davis Cup, coming through 6-4, 5-7, 6-7 (5), 6-3, 6-4 in 5 hours, 7 minutes to gain a measure of revenge after losing the Olympic final to Murray last month. It was the longest match of both players' careers.
Pella beat Kyle Edmund 6-7 (5), 6-4, 6-3, 6-2, meaning the Argentines can clinch victory with a day to spare in Glasgow if they win the doubles on Saturday. Federico Delbonis and Leonardo Mayer are scheduled to play the Murray brothers, Andy and Jamie.
Whether Andy Murray plays is open to question.
Being taken the distance against Del Potro was exactly what Murray didn't need at the end of his long summer of tennis in which he won both the Wimbledon and Olympic titles for the second time. He looked almost out on his feet at times in an energy-sapping final set, and couldn't handle the barrage of forehand shots by the rejuvenated Del Potro.
Del Potro gained the crucial break in the fifth set at the third opportunity, reaching Murray's angled volley with a forehand winner down the line to go 4-3 ahead, and he served out for the match, clinching victory with an ace and a big growl.
Murray had never previously lost a home singles match in the Davis Cup.
Del Potro, the 2009 US Open champion, is a force in tennis once again after returning from three wrist operations that nearly ruined his career. He is Argentina's top player but is ranked a lowly No 64 on his comeback trail, meaning he had to play Murray in the opening match.
Argentina is playing its 11th Davis Cup semifinal in 15 years. The south American country has never won the team event, finishing runner-up in 1981, 2006, 2008, and 2011.
Croatia vs France
World number 11 Marin Cilic beat talented youngster Lucas Pouille in four sets to level the Davis Cup World Group semi-final tie between Croatia and France at 1-1 on Friday.
Cilic won 6-1, 7-6 (7/4), 2-6, 6-2 in Zadar to haul Croatia level after Richard Gasquet had given France the advantage by beating rising star Borna Coric in the opening rubber.
Pouille, a quarter-finalist at the recent US Open, was playing in just his second Davis Cup match and Cilic, the 2014 US Open champion, made his experience pay after recovering from a wobble in the third set.
Late call-up Gasquet beat Coric 6-2, 7-6 (7/5), 6-1 earlier in the day.
Gasquet, 30, was drafted in after Jo-Wilfried Tsonga and Gael Monfils pulled out with knee injuries and the world number 17 made the most of the opportunity against the 19-year-old Coric on Zadar's indoor hard courts.
Gasquet looked initially set to miss out because of his own struggle with back and chest injuries over the summer, and even lost in the first round of the US Open to Britain's Kyle Edmund.
Cilic is expected to team up with Ivan Dodig in Saturday's crucial doubles against French pair Pierre-Hugues Herbert and Nicolas Mahut.
Australia vs Slovakia
Nick Kyrgios and Bernard Tomic claimed straight set victories to give Australia a commanding 2-0 lead over Slovakia in Sydney.
The 15th-ranked Kyrgios shrugged off recent hip problems to whip through Andrej Martin 6-3, 6-2, 6-4 while the 21st-ranked Tomic completed a 7-6 (7/5), 6-4, 6-4 win over Jozef Kovalik.
Australia will stay in the premier World Group next year if they win one further match in the best-of-five rubber at Sydney's Olympic Tennis centre.
Kyrgios was expected to have little trouble with the world No127 Martin and cruised to victory in 1hr 40min to take his Davis Cup singles record to 4-3.
It came just over a week after he was forced to quit his third-round US Open match against Ukraine's Illya Marchenko with a hip injury.
But the temperamental 21-year-old star showed little inconvenience to put away Martin despite plugging up a nose bleed early in the final set.
Tomic won a first-set tiebreaker and raced to a two sets to love lead before his game dropped off. He regrouped to take the match in three sets in just under two hours.
He improved his impressive Davis Cup singles record to 17-4.
Tomic was at the centre of a foul-mouthed controversy at the US Open last month when he became embroiled in a lewd exchange with a heckler on the way to his first-round exit to Damir Dzumhur of Bosnia.
Australia, who lost to the United States in this year's first round, are looking to maintain their three-year stay in the World Group.
Slovakia, who have come to Australia without their two leading stars -- 31-ranked Martin Klizan and 102-ranked Lukas Lacko -- are up against ending a 10-year absence from the World Group.
The Slovaks, captained by Olympic gold medallist Miloslav Mecir, have lost all five of their World Group playoffs since losing to Chile in the World Group first round in 2006.
Japan vs Ukraine
Japan grabbed the initiative as Taro Daniel and Yoshihito Nishioka put the home side on the brink of victory.
With world number five Kei Nishikori rested for the opening day's singles following his exertions over the summer, Daniel set the tone by beating an ailing Sergiy Stakhovsky 7-6, 7-6, 6-1 in sweltering conditions in Osaka.
Nishioka then upset Illya Marchenko 6-4, 5-7, 6-4, 7-5 to leave Japan needing to win Saturday's doubles to retain their World Group status next year.
"It's normal he would be a bit deflated after losing two tiebreaks," said world number 88 Daniel after seeing off Stakhovsky, a late replacement for Artem Smirnov.
Nishioka was the underdog against Marchenko, who came into the rubber ranked a career-high 50th in the world.
But as the floodlights came on, the power seemed to drain from the Ukrainian, who paid tribute to his conqueror.
Nishikori, who won bronze at the Rio Olympics before reaching the semi-finals of the US Open last week, is scheduled to play in Saturday's doubles in partnership with Yuichi Sugita.
Here are all the big World Group results at a glance:
Winners to World Group Final, 25-27 November
Argentina 2, Britain 0
Juan Martin del Potro, Argentina, beat Andy Murray, Britain, 6-4, 5-7, 6-7 (5), 6-3, 6-4.
Guido Pella, Argentina, beat Kyle Edmund, Britain, 6-7 (5), 6-4, 6-3, 6-2.
Croatia 1, France 1
Richard Gasquet, France, beat Borna Coric, Croatia, 6-2, 7-6 (5), 6-1.
Marin Cilic, Croatia, beat Lucas Pouille, France, 6-1, 7-6 (4), 2-6, 6-2.
Winners to 2017 World Group; losers to 2017 Zonal I Groups
Uzbekistan 1, Switzerland 1
Denis Istomin, Uzbekistan, beat Antoine Bellier, Switzerland, 6-3, 6-2, 6-4.
Henri Laaksonen, Switzerland, beat Farrukh Dustov, Uzbekistan, 6-2, 6-2, 6-2.
Belgium 2, Brazil 0
David Goffin, Belgium, def. Thiago Monteiro, Brazil, 6-2, 6-2, 6-0.
Steve Darcis, Belgium, def. Thomaz Bellucci, Brazil, 6-7 (5), 6-1, 6-3, 6-3.
Australia 2, Slovakia 0
Nick Kyrgios, Australia, beat Andrej Martin, Slovakia, 6-3, 6-2, 6-4.
Bernard Tomic, Australia, beat Jozef Kovalik, Slovakia, 7-6 (5), 6-4, 6-4.
Canada 1, Chile 0
Frank Dancevic, Canada, beat Christian Garin, Chile, 6-3, 6-7 (5), 6-1, 6-4.
Spain 2, India 0
Feliciano Lopez, Spain, beat Ramkumar Ramanathan, India, 6-4, 6-4, 3-6, 6-1.
David Ferrer, Spain, beat Saketh Myneni, India, 6-1, 6-2, 6-1.
Germany 2, Poland 0
Jan-Lennard Struff, Germany, beat Kamil Majchrzak, Poland, 6-7 (8), 6-3, 5-7, 6-2, 6-1.
Florian Mayer, Germany, beat Hubert Hurkacz, Poland, 1-6, 7-6 (6), 6-4, 7-5.
Japan 2, Ukraine 0
Taro Daniel, Japan, beat Sergiy Stakhovsky, Ukraine, 7-6 (4), 7-6 (2), 6-1.
Yoshihito Nishioka, Japan, beat Illya Marchenko, Ukraine, 6-4, 5-7, 6-4, 7-5.
With inputs from agencies