Taylor Fritz beat his friend and US rival Frances Tiafoe in two closely fought sets to win the Japan Open on Sunday, saying "I had to play my absolute best to beat him today".Third-seeded Fritz claimed the title 7-6 (7/3), 7-6 (7/2), and will break into the top 10 for the first time on Monday with a new ranking of eight.The 24-year-old described his victory as "really crazy", coming immediately after a week of Covid-19 hotel quarantine in Seoul that forced him to withdraw from the Korea Open.But his first words on court after winning were for fourth-seeded Tiafoe, also aged 24, who has been in the spotlight since he stunned Rafael Nadal to reach the US Open semi-finals."First off, I wanna congratulate Frances on a great week, I mean, he's been on fire recently, and I had to play my absolute best to beat him today," Fritz said."We've spent a lot of time together the last couple weeks, he's one of my really close friends, and I'm sure it's not going to be the last time we play for a big-timer."Both players were in the Rest of the World Team that beat Europe last month at the Laver Cup in London for the first time in the competition's history.