London, England, 26 June 2013 | AAP

Bernard Tomic dug deep to secure a gutsy five-set upset win over American 21st seed Sam Querrey on Tuesday to reach the second round at Wimbledon.

Despite blowing a two-set lead, and calling for a doctor midway though the match due to dizziness, Tomic pulled out something special in a 7-6(6) 7-6(3) 3-6 2-6 6-3 victory.

The Australian world No.59 will next face American James Blake, who defeated Dutchman Thiemo de Bakker 6-1 6-3 6-2.

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Tomic joined Samantha Stosur and Lleyton Hewitt in the second round.

The first two sets were dominated by strong service games, though Tomic did well to fight back from a break down midway through the opening set.

He won two tiebreakers to take a commanding lead but big-serving Querrey secured a crucial break and held on to claim the third set.

Querrey carried the momentum into the fourth set and Tomic looked to be tiring alarmingly.

He called for a doctor after Querrey had gone 4-1 up, complaining of poor vision and dizziness.

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Querrey went on to level the match and it looked Tomic was going to fade out of the match.

However the 20-year-old lifted and served strongly early in the deciding set.

The decisive game came when Tomic was 4-3 up, breaking Querrey’s serve with a succession of brilliant winners and then serving out the match with ease in the next game.

Earlier, Stosur blasted her way into the second round with a dominant 6-1 6-3 win over Slovakian teenager Anna Schmiedlova.

The 14th seed declared it one of her better performances on grass as she set up a second-round clash with Russian Olga Puchkova.

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“I was really pleased with the way I played,” Stosur said.

“I feel pretty good going into the next round.”

A strong fightback proved in vain for James Duckworth in a 6-4 6-2 3-6 4-6 6-1 loss to a fellow qualifier, American Denis Kudla.

Wildcard Matt Ebden became the fourth Australian man to lose in the first round when he fell in a 6-2 6-4 6-3 defeat to Japanese 12th seed Kei Nishikori.

Hewitt upset Swiss 11th seed Stanislas Wawrinka on Monday to set up a second round match against German Dustin Brown on Tuesday.