INDIA, Jan. 28 -- ATP World No. 100 Tennys Sandgren became the victim of an incredible fightback from 20-time grand slam champion Roger Federer in the quarter-finals of the 2020 Australian Open. After trailing 2 sets to win, Federer saved a total of 7 match points while putting in a mesmerising show to beat the American 3-6, 6-2,6-2, 7-6 6-3 on Tuesday.Going hasn't been easy for Federer since his second-round win over Filipi Krajinovic. In the third and the fourth round of the first grand slam of the season, the Swiss maestro defeated John Millman (5-setter) and Marton Fucsovics (4-setter) to set up a clash with Sandgren in the last 8. After coming out victorious in a pretty straight forward 3-6 win over Sandgren in the first set, Federer s...