World number one Aryna Sabalenka has survived her toughest test of the tournament to beat Wimbledon champion Linda ​Noskova 7-6(7/1), 3-6, 7-6(10/7) and reach the US Open semifinals for a sixth consecutive year.

Two-time defending champion Sabalenka had not dropped a set before facing the Czech sixth seed, who fired ​18 aces and saved ‌seven of nine break points but faltered when leading by a break at 2-4 in the final set.

Sabalenka, chasing a third straight title at Flushing Meadows, next plays Jessica Pegula.

"What a battle. What ⁠an incredible player she is. I'm speechless right now because ‌I was pushing myself to ​the limit this match," ‌said Sabalenka, who has now won 21 of her past 22 matches at the year-end grand slam.

"In the third set I honestly thought, 'That's it, the match is over.' Probably that's what helped me to kind of feel loose and just go after my shots. Super happy to get this win."

By reaching the final four for a sixth straight time, Sabalenka matched the 2011-2016 run of Serena Williams, during which she won three of her six US Open crowns.

The Belarusian broke in the second game, whipping a forehand into the corner that Noskova did not even attempt to chase down, but the Czech broke back with a pair of powerful groundstrokes from the baseline in ​the ‌ninth.

Sabalenka, who reached a record 21 consecutive tiebreak wins at the slams earlier this year, was completely in her element in the opening-set breaker, ⁠where she sprinted through the first ‌six points.

But her firepower deserted ‌her in the second set and she struggled to contain Noskova's serve before handing the ‌Czech a 4-2 lead with a double fault.

After levelling the contest at one set all, Noskova set about pressing home her ‌advantage.

Sabalenka ​screamed in frustration when ⁠a pair of double faults midway through the third set helped her opponent secure another break.

Noskova seemed to be heading for an upset win before Sabalenka recovered her poise to level the contest in the ⁠eighth game.

And the Belarusian was right at home again in the decisive tiebreak, clinching it with an ace ‌before giving ‌credit to the fans for helping to propel her to ​the win.

Pegula reaches third straight US Open semifinal

Jessica Pegula reached the US Open semifinals for a third straight year, coming from a set down to beat Emma Navarro 3-6, 6-4, 6-3 in an all-American clash.

The 32-year-old will face two-time defending champion Aryna Sabalenka in a rematch of the 2024 final after securing her fifth straight win over her compatriot, including a victory at last month's Cincinnati Open.

The clash, dubbed by American media as the "Battle of the Billionaires" because of their backgrounds, began more than an hour later than scheduled after Frances Tiafoe's marathon victory over Alex Michelsen in another all-American contest.

The wait did little to help either player find their rhythm, with the match instead marked by errors and few sustained bursts of momentum.

The 26th seed had the edge in a scrappy opening set as both players struggled to settle. They traded early breaks and each hit five double faults, with an extra break allowing Navarro to move one set ahead.

The miscues continued in the second, but Pegula found a slight improvement that allowed her to level the match, finishing a long exchange with a fine forehand winner to make it one set apiece.

Pegula carried that momentum into the decider, where an extra break put her in control before she closed out the victory.

Reuters/ABC