MELBOURNE, Australia - US Open champion Naomi Osaka kept her Grand Slam match winning streak alive in Melbourne, rallying from a set down to defeat No.13 seed Anastasija Sevastova, 4-6, 6-3, 6-4 to reach her first Australian Open semifinal.

Osaka soared to her maiden Grand Slam title last summer and won an 11th straight match on the major tournament level on Monday after one hour and 47 minutes on Rod Laver Arena.

Sevastova made it to the semifinals in Flushing Meadows - her best-ever result at a Grand Slam event - and narrowly lost to Osaka to kick off the season at the Brisbane International. Eager for another shot at the upset, the Latvian scored the only service break of the opening set and held on without facing a break point of her own to move within six games of the quarterfinals.

No stranger to a tricky situation, Osaka stood just two games from defeat in her last match against Hsieh Su-Wei before turning the tables on the crafty veteran. Saving a break point early in the second, the 21-year-old broke for the first time to lead 4-2, and forced a deciding set shortly thereafter.

"Like in Brisbane, I played the same sort of match. I lost the first set and I managed to win again. And it was against the same player. So I think just having that experience," Osaka said after the match.

"I think the biggest thing for me is the belief. I think I believe in myself more this year than I have last year."

Osaka began the decider with all the momentum and a chance for a double break lead after winning the first two games. 

Sevastova pushed back, saving a break point and evening the score after a dramatic sixth game that featured a 0-40 lead and six total break point opportunities.

Unlike the contest between Elina Svitolina and Madison Keys earlier in the afternoon, the long game hardly proved lethal for Osaka, who promptly broke in the next game and found herself serving for the match at 5-4.

Down three match points, Sevastova swung a forehand away at net to save the first, but Osaka wouldn't be deterred, putting away a searing forehand of her own to clinch her spot in the last eight.

In all, Osaka struck a stunning 51 winners to 43 unforced errors, proving especially clutch on break point opportunities, converting three of four. Winning 70% of poitns behind her first serve, she struck seven aces to just one double fault.

Up next for the No.4 seed is No.6 seed Svitolina, who will also be looking for her first Australian Open semifinal. The reigning BNP Paribas WTA Finals Singapore presented by SC Global champion won both of their 2018 meetings in straight sets - most recently at the Miami Open, when she ended Osaka's winning streak after winning the BNP Paribas Open in Indian Wells and shocking 23-time Grand Slam champion Serena Williams in Crandon Park.

"I know she played well at the end of the year, she won the WTA Finals. Personally, I was really happy for her, because I know that everyone was sort of writing her off, because she wasn't doing well leading up to that," Osaka assessed.

"I know she's playing well again here, because I'm going to play her and she's still here. I have played her multiple times now, and I know she's a very consistent player and when she has the chance she does like to attack. I think playing her is going to be very difficult for me."