Aslan Karatsev pushed past Frances Tiafoe in the opening round of the Kinoshita Group Japan Open, securing the match with a closely contested straight-sets win 6-3, 7-6 (4).

World No. 50 Karatsev made his debut at the ATP 500 tournament in Tokyo against the reigning runner-up and World No. 14 Tiafoe. The American had reason to be confident coming into the match as he led their head-to-head 2-0, having most recently defeated the Russian at the DC Open in August.

The first set began with both players holding serve successfully until they were even at 3-3. It was at this point that Karatsev began to push ahead, building up two break points. Tiafoe then double faulted to give the 30-year-old a break in the opener.

Karatsev was then able to successfully hold until he could serve for the set. He amassed two set points before an unforced error from Tiafoe sealed the deal.

Things were trickier for Karatsev in the second set as Tiafoe came back fighting, winning his first service game W-0. At this point, it looked as though Karatsev could be in trouble as his first game went to a deuce. However, he was ultimately able to save himself from a break by acing his opponent.

Nevertheless, Tiafoe came back immediately to build a 0-40 lead in Karatsev's next service game, which he then successfully converted into a break. The American then held his serve for a 4-1 lead and it looked as though the match would be going to a decider.

However, Karatsev was not about to give up without a fight and held to avoid a double break before securing two break points of his own at 4-2. He then pulled off a well-timed return to put the set back on serve.

After that, both players held their service games until a tiebreak was required. Tiafoe started the tie strongly, building up a 4-0 lead to push the match closer and closer to a decider, but Karatsev was able to keep calm and make up the gap with some more strong returns.

He then pushed ahead to get two match points, successfully converting the first one after Tiafoe hit the ball out.

Karatsev will face the winner of the match between Hubert Hurkacz and Zhizhen Zhang in the second round.