Australian Open continued to showcase a drama-filled tournament on the fourth day as American Jenson Brooksby knocked out the tournament’s second seed Casper Ruud 6-3, 7-5, 6-7(4), 6-2 at the Rod Laver Arena.

His win is the second-biggest upset of the tournament this year after his countryman Mackenzie McDonald’s shock win over Rafael Nadal the previous day.

The American frustrated Ruud from the beginning, using his backhand to pin the two-time major finalist to his weaker corner for much of the three-hour, 55-minute match. Brooksby also dominated the longer exchanges, winning 55 of the 80 rallies that went on for 9 shots or more.

The 22-year-old also took 9 of his 13 break opportunities with luck bailing him out a few times as well.

After the second set, Ruud had to leave the court for a medical timeout.

The World No. 3 dug deep to force a fourth set after saving three match points and battling back from 2-5 in the third set just to extend the contest but was outclassed in the decider.

Jenson Brooksby will look to keep his magical Australian Open run going when he faces countryman Tommy Paul next who booked his third-round place with a 6-2, 2-6, 7-6, 6-7(4), 6-3, 6-4 win against 30th seed Alejandro Davidovich Fokina.

Taylor Fritz and Alexander Zverez also joined the upsets list.

Fritz, fresh off helping team USA win the United Cup, was beaten 6-7 (4/7), 7-6 (7/2), 6-4, 6-7 (6/8), 6-2 by Alex Popyrin while Zverev, playing his first grand slam since the French Open was sent packing by Michael Mmoh 6-7, 6-4, 6-3, 6-2.

Andrey Rublev, Dan Evans and Holger Rune managed to reach the next round unscathed.

Andy Murray, Novak Djokovic and Alex de Minaur, among others, will also take the court later today.