What little remained of the dwindling spring sports calendar was wiped nearly clean Friday. The Masters golf tournament and Boston Marathon became the latest iconic events to announce postponements in the wake of the public health crisis wreaked by the novel coronavirus.

Virtually every major U.S. sporting event scheduled for the coming weeks was either shelved or canceled, and many leagues and organizers around the globe followed suit. European soccer ground to a halt Friday, and NASCAR and IndyCar postponed upcoming races.

They were among the last holdouts. The NBA and NHL already suspended their seasons; Major League Baseball delayed its Opening Day; and the NCAA canceled all of its championship tournaments — all happening in a dizzying 48-hour period this week that was unlike anything the sports world has experienced.

Augusta National Golf Club spent the week weighing its options for hosting the Masters before announcing Friday morning that the event, steeped in tradition and covered in azaleas, would not start April 9 as planned. Tournament officials offered no timeline on when it might be rescheduled but were hopeful it could still be held this year.

The decision came less than 24 hours after the PGA Tour canceled the final three rounds of the Players Championship, as well as all other Tour events through April 5. The Masters was scheduled to take place the following week, which means the world’s top golfers probably won’t play a tournament again until at least mid-April.

“Ultimately, the health and well-being of everyone associated with these events and the citizens of the Augusta community led us to this decision,” Fred Ridley, chairman of Augusta National Golf Club, said in a statement. “We hope this postponement puts us in the best position to safely host the Masters Tournament and our amateur events at some later date.”

Around the same time Friday, Boston Mayor Martin J. Walsh appeared at a news conference and announced the Boston Marathon, originally scheduled for April 20, would be postponed until Sept. 14, another proactive measure by event organizers to minimize large gatherings and help stem the outbreak of the virus that causes covid-19.

“Our expectation and hope right now is that this day will get us to a safer date,” Walsh said. “We want to make sure that we keep people safe. … That’s what all this is about."

Moving the marathon — one of the largest and most prestigious distance races in the world — is “a very big undertaking,” Walsh said, adding that the proposed new date of the race “jumped around like a pinball” as officials discussed logistics. Questions about temperatures and possible conflicts with activities at local schools had to be considered.

The marathon winds its way through eight Boston-area communities over the 26.2 miles, attracting more than 30,000 runners and crowds that annually exceed 500,000 along the route. The race began in 1897 and has been altered only once before: in 1918 during World War I, when a military relay race was held instead.

Runners had been bracing for the postponement; other marathons across the globe similarly were impacted by the coronavirus, with Rome canceling its race and Paris moving its event to October. On Friday, race officials also delayed the London Marathon until Oct. 4. It had been scheduled for April 26.

NASCAR, which earlier this week had planned to stage its next two Cup Series races without fans present, reversed course Friday, postponing both Sunday’s race at Atlanta Motor Speedway and the March 22 race at Homestead-Miami Speedway.

“We believe this decision is in the best interest of the safety and well-being of our fans, competitors, officials and everyone associated with our sport,” the circuit said on statement. “We will continue to monitor this dynamic situation as we assess future race events.”

Sunday’s IndyCar race, which likewise was to be run in the absence of fans in St. Petersburg, Fla., also was canceled, along with all other IndyCar races through April.

The U.S. Olympic wrestling trials, scheduled for April 4-5 in University Park, Pa., were also postponed, making the event the first U.S. trials to be impacted. The International Olympic Committee, meanwhile, has remained steadfast in its stance that the Tokyo Games will take place as scheduled this summer.

The mass postponements are sure to prompt creative schedule-shuffling with leagues, broadcasters, sponsors and municipalities. Rescheduling the Masters, usually golf’s first major of the year, could be especially tricky, and tournament officials might have to target September or later. There is no hole on the summer golf calendar that isn’t otherwise occupied by an existing PGA Tour event. In addition, Augusta National holds its tournament in April to take advantage of ideal conditions. Temperatures are so hot in the summer that the course is closed, and it doesn’t reopen to members until early fall.

The PGA Tour concludes its season Aug. 30 in Atlanta, just a couple of hours west of Augusta. The Masters could seek to host its tournament shortly after that, before international players return to their home countries.

The Masters has been held in Augusta, Ga., every year since 1934, except for 1943-45, when it was canceled because of World War II.

“Unfortunately, the ever-increasing risks associated with the widespread Coronavirus covid-19 have led us to a decision that undoubtedly will be disappointing to many, although I am confident is appropriate under these unique circumstances,” Ridley said in the statement.

The soccer world has been rocked by the disease with a high-profile player and a manager testing positive for the virus. While Concacaf suspended all competitions for the next 30 days, UEFA, the governing body for European soccer, announced that all round-of-16 matches in its Champions League and Europa League club competitions scheduled for next week were postponed. Because those matches will not be played as scheduled, the March 20 quarterfinal draws also were put off.

“Further decisions on when these matches take place will be communicated in due course,” UEFA said in a statement.

A number of European professional leagues also suspended operations Friday because of the coronavirus, including the Premier League, which will halt play until at least April 3. That decision was made just one day after Arsenal Manager Mikel Arteta tested positive for the coronavirus and its entire first team placed itself in isolation. Chelsea’s Callum Hudson-Odoi also tested positive, and players from four other clubs — Bournemouth, Everton, Leicester and Watford — were in self-isolation after showing symptoms.

Top leagues in France and Germany also suspended play, falling in line with counterparts in Spain, Italy, Portugal and the Netherlands that had already shut down because of the coronavirus.

With club competitions across Europe halted and season completions delayed, UEFA must decide what to do with this summer’s Euro 2020 tournament. Speculation centered on a postponement until 2021.

In many ways, the most surprising developments this week revolved around the organizations that opted to continue holding events.

Mexico’s top soccer league is one of the few not to shut down amid the coronavirus outbreak. Liga MX matches through the weekend were still set to be played — with fans allowed to watch in most cases — though pregame handshakes among players, officials and child mascots would not be allowed.

And UFC President Dana White said Thursday that his company would continue to stage its upcoming mixed martial arts shows, beginning with one Saturday in Brazil that won’t have fans in attendance. The following weekend, a UFC card in London will “proceed as planned,” he said.

The company is moving its March 28 event from Columbus, Ohio, where the governor has called for no spectators at indoor sporting events, to a UFC-owned arena in Las Vegas.

White said that the UFC has always gone “overboard with health and safety” and that he even consulted President Trump and Vice President Pence this week.

“They’re saying, ‘Be cautious, be careful, but live your life and stop panicking,’ ” White told ESPN. “Everybody is panicking, and instead of panicking, we’re actually getting out there and working with doctors and health officials and the government to figure out how we keep the sport safe and how we can continue to put on events.”