De Minaur forces Davis Cup tie decider

Alex de Minaur has sent Australia's Davis Cup qualifier with Hungary into a fifth and deciding rubber with a rousing win over Marton Fucsovics.

De Minaur came out on top in the marquee match-up between the two nations' No.1s with an electrifying 7-6 (7-4) 6-4 victory that locked the Sydney tie up at 2-2.

Unless there's a late change from the respective captains, Thanasi Kokkinakis and Zsombor Piros will battle it out in a winner-takes-all showdown at Ken Rosewall Arena.

The triumphant team will progress to the September finals of the competition.

Hungary had taken a shock 2-1 lead with a stunning doubles win in Saturday's first match.

Hungarian captain Zoltan Nagy's late team change paid huge dividends when Mate Valkusz and Fabian Marozsan upset John Peers and Australian Cup debutant Luke Saville 6-4 6-4.

After initially naming Fucsovics to partner Marozsan at Thursday's draw, Nagy opted to rest his singles spearhead for the first reverse singles match against de Minaur.

The visiting skipper only made the announcement half an hour before the doubles, but Valkusz -- ranked 1312th in doubles and the world No.439 singles player -- was an unexpected success.

"It's crazy," Valkusz said after winning his first-ever Davis Cup match.

Peers, a former Australian Open doubles champion and a winner of the Olympic bronze medal in mixed last year with Ash Barty, cut a forlorn figure after double-faulting on match point to hand Hungary victory.

He dropped serve three times in the first set as the home fans, under the closed roof at Ken Rosewall Arena, watched on almost in disbelief.

"I don't think we played the best match we could have but I feel like those guys played a really good level and didn't really let us settle," Peers said.

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