Stefanos Tsitsipas won his singles contest before returning to court with Andrey Rublev to triumph in doubles as Team Europe swept all matches on Saturday and are one victory away against Team World to maintain their iron grip on the Laver Cup.
Team Europe have won all three editions of the Laver Cup so far and were on the cusp of a fourth after the Bjorn Borg-captained side went ahead 11-1 at the end of second day's play at Boston's TD Garden.
The absence of Roger Federer, Rafa Nadal and Novak Djokovic for this year's event has proved to be no hindrance as Team Europe maintained a spotless record in the six singles matches over the first two days.
Named after Australian great Rod Laver, the three-day team event pits six of Europe's top players against six of their counterparts from the rest of the world, with four matches played each day - three singles and a doubles.
Each win is awarded one point on Friday, two points on Saturday, and three points on Sunday, with the first team to reach 13 points declared winner of the event, which was cancelled last year due to the COVID-19 pandemic.
In Saturday's first match, world number three Tsitsipas did not leave the court against Nick Kyrgios but required some time to replace a worn-out pair of shoes during a 6-3 6-4 win.
Tsitsipas came under scrutiny at the US Open for both the timing and length of his mid-match bathroom breaks, which critics considered unfair gamesmanship. But this time he was in control of the match and had a clear reason for the stoppage.
Early in the second set, Tsitsipas interrupted his own service game at 15-15 and took several minutes installing new laces before ultimately deciding to put on fresh shoes, given the original pair did not stand up well to the indoor surface.
"It's not the best advert for the shoe I guess, but look at it, it's absolutely battle-weary from the amount they slip and slide around," the Eurosport commentator said.
"I wonder if Kyrgios is tempted to say something like, 'Is this going to take about eight minutes? What's going on here?!'"
The Greek returned to the multipurpose indoor arena - also used by the NBA's Celtics and NHL's Bruins - with Russian world number five Rublev for the final match on the second day and rallied to beat the pairing of American John Isner and Australian Kyrgios 6-7(8) 6-3 (10-4).
Germany's Alexander Zverev, ranked fourth in the world, also needed the 10-point match tiebreaker in the final set to tame big-serving Isner 7-6(5) 6-7(6) 10-5.
US Open champion Daniil Medvedev had a more comfortable outing in the night session against Canada's Denis Shapovalov and won 6-4 6-0.
Zverev and Rublev will look the settle the fate of the Laver Cup early on Sunday when they team up for the opening doubles match against Shapovalov and American Reilly Opelka.
Following the doubles, the German is scheduled to be back on court soon for his singles contest against Canadian Felix Auger-Aliassime.
Medvedev will play Argentina's Diego Schwartzman in the third match before Tsitsipas draws the curtains on the event, which moves to the O2 Arena in London in 2022, with his contest against Isner.
