With the Aussie Open in the rearview, we look at risers and sinkers in the ATP rankings.

Stefanos Tsitsipas has reached another career milestone on the heels of his breakout performance at the Australian Open. The Greek rises to a career-high ranking of No.12 in the world this week and now sits just 335 points out of the Top 10.

See the full ATP Rankings Breakdown Here

The 20-year-old has just 154 points to defend over the next two months, between now and the end of the Miami Open.

Tsitsipas was one of three #NextGenATP players that hit a career-high ranking inside the Top 30 this week, along with No.28-ranked Alex de Minaur and No.30-ranked Frances Tiafoe.

New Career-High Rankings for #NextGenATP Players
12 @StefTsitsipas GRE 20
28 @AlexdeMinaur AUS 19
30 @FTiafoe USA 21
118 Miomir Kecmanovic SRB 19
124 @AlexeiPopyrin99 AUS 19
182 Rudolf Molleker GER 18
183 @W412Yosuke JPN 20
194 @MikaelYmer SWE 20
197 Jurij Rodionov AUT 19

— ATP Media Info (@ATPMediaInfo) January 28, 2019

At the top of the rankings World No.1 Novak Djokovic increased the gap between himself and No.2 Rafael Nadal to 2,625 points, while Roger Federer slipped out of the Top 5 for the first time since March of 2017, dropping from No.3 to No.6.

The biggest riser inside the Top 20 was France’s Lucas Pouille. The 24-year-old climbed 14 spots from No.31 to No.17. Pouille wasn’t the only Frenchman making a big jump. Aussie Open doubles champion Pierre-Hugues Herbert also reached a career-high singles ranking of 44 thanks to his third-round showing at Melbourne.

American Taylor Fritz jumped a career-high ranking of 40 after reaching the third round in Australia and winning the Newport Beach challenger.

The biggest droppers inside the Top 100 were Hyeon Chung, who fell 25 spots to No.50, Tennys Sandgren, who fell 34 spots to No.75 and Tomas Berdych, who fell 22 spots to No.79. Kyle Edmund and Nick Kyrgios each dropped 15 spots, with Edmund falling to No.29 and Kyrgios falling to 67.

#ATP weeks at No.1 and year-end No.1 finishes. These are the top 10 in terms of total weeks at No.1…

Look like Novak Djokovic has some room to climb. pic.twitter.com/v6ec4y6dXJ

— TennisNow (@Tennis_Now) January 30, 2019

The Spaniard says that his defensive skills weren't polished enough to allow him to play at Djokovic's level on Sunday in Melbourne

Photo: Mark Peterson/ Corleve

Rafael Nadal worked extremely hard to give himself a shot to win this year’s Australian Open. The 17-time major champion beefed up his serve and his overall aggression in order to minimize his time on court and his plan worked to perfection as he raced through six rounds down under without dropping a single set. But Nadal says that there was one thing missing from his game in Australia, and it left him exposed against Novak Djokovic in the final: DEFENSE.

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“I think I was playing great during the both weeks in offensive positions,” Nadal told reporters on Sunday night. “In defensive positions, I practiced what I practiced. I practiced well, very well I think, but because of the things that happened to me in terms of surgery, then what happened in Abu Dhabi, I was not able to work that much the defensive game. I worked a lot on the offensive game, but not that much on the defensive game.”

Nadal had off-season ankle surgery and was in a rush to return to form in January. He was forced to withdraw from a match at Abu Dhabi in late December then pulled out of Brisbane in early January.

Nadal says he felt like a defensive base would have given him a better chance to employ aggression on his terms in the final, but Djokovic’s absurd level would not let him do that.

“To play against a player like him, playing the way he played tonight, I needed that defensive game to finally have the chance to be offensive, no?” he said. “When he was hitting, is true that maybe was difficult to beat him even if I was at my 100%. But probably will be a little bit more fight.

Still Nadal has to be pleased with his effort and the fact that he finished the tournament without aggravating any injuries. He will begin this week at No.2 in the rankings, 2,635 points behind No.1 Djokovic.

“I played fantastic tennis during both weeks, is true, but probably playing that well, I didn't suffer much during the both weeks,” Nadal told reporters after the final. “Five months without competing, having that big challenge in front of me, I needed something else. That something else probably today, I don't have it yet. That's my feeling, to compete at this super high level.”