Exciting Spanish teenager Rafael Nadal fought back from match point down to dump 15th seeded Russian Mikail Youzhny out of the Australian Open.

The 18-year-old Spanish left-hander was staring at defeat at 4-5, advantage in the fourth set, but the Russian missed his winning chance with a backhand volley to trigger an amazing fightback by Nadal.

The 56th-ranked Nadal stormed home in the final set to clinch a 6-1, 4-6, 4-6, 7-5, 6-3 in three hours and 37 minutes and set up a third-round match with American qualifier Bobby Reynolds on Saturday.

Nadal, the nephew of former Spanish international and Barcelona football legend Miguel Angel Nadal, thrilled the centre-court crowd with his exhaustive court coverage and a willingness to chase lost causes, while Youzhny frittered away his opportunities.

Youzhny fell behind 0-4 in the fifth set after an over-hit backhand on break point, but the Russian clawed back a break when Nadal mis-hit a forehand out of play at 15-40 on his serve in the sixth game.

Games went with serve until the ninth when Nadal conjured a tremendous cross-court backhand to bring up his first and only match point and then took the match with a committed pick-up of a Youzhny drop shot which the Russian blocked out of court.

Nadal has repeated last year's effort of reaching the third round of the Australian Open.

He lost to Australian Lleyton Hewitt in three high-quality sets last year in a night match on Rod Laver Arena, two of them dramatic tiebreakers.

Nadal last month became the youngest man to play on a Davis Cup-winning team for Spain in the final against the United States in Seville.

In the final, Nadal defeated world number two Andy Roddick in four sets to guide Spain to victory 3-2.