Serena Williams survived the toughest test of her Wimbledon campaign so far as she came from a set down to beat Camila Giorgi and reach the semi-finals.

Williams' seemingly inevitable march to the final of a women's singles tournament in which none of the top 10 seeds remain continued at pace against Evgeniya Rodina as she eased into the last eight, but the seven-time Wimbledon champion needed to use much more of her reserves against Giorgi.

The Italian's comments ahead of the match that she does not follow tennis will have raised eyebrows but, competing in her first grand slam quarter-final, she troubled Williams significantly with her movement and power and took the first set.

However, a huge missed opportunity to break in the second proved the turning point and Williams hit the accelerator, outgunning Giorgi in a 3-6 6-3 6-4 triumph that edges her closer to the final and a record-tying 24th slam. Julia Goerges will be the next to try to end her hopes.

Giorgi went into the match having served the most double faults in the tournament and duly committed one in the first game, but recovered her composure to save it with a scintillating cross-court forehand.

Whereas Rodina seemed overawed by facing Williams on Centre Court in the fourth round, such nerves were not apparent in Giorgi, who benefited from a poor line call to go a break up.

Williams opted not to challenge when she saw a shot called long, although Hawk-Eye proved it was actually in, and Giorgi went on to bring up two break points, with Serena then mishitting wide to surrender the game.

Going a break down elicited a typically angry response from Williams, who surged into a 40-0 lead on Giorgi's serve in the subsequent game. However, Giorgi came through a huge test of character as she saved three break points and then a fourth with the help of a fierce forehand as she earned an important hold.

Giorgi was excellent off both wings in the opener and won her first set in four meetings with Williams as a brilliant backhand gave her two set points and an errant forehand followed from the American.

The first sign of the pressure getting to Giorgi came in the third game of the second when she forged a 30-0 lead on the Williams serve. An excellent return put her in position to gain two break points, but Giorgi let the opportunity slip by hitting a backhand long, and she paid the price as Williams held and then broke for the first time in the match, finding the angle with a rasping forehand.

Though she was able to halt Williams' momentum and a run of four successive games, Giorgi could not prevent her from forcing a decider, the 36-year-old letting out a huge roar as she clinched the second set.

By that point it was obvious Giorgi was struggling to cope with Williams' jump in intensity and it did not take the tournament favourite long to strike in the third. A blistering forehand return gave her three break points in the third game, and she snatched the first with an outstanding off-balance backhand down the line.

Giorgi served to stay in the match in confident fashion with a hold to love, but Williams then did the same as Giorgi's gallant effort came to an end with a tired forehand into the net.

STATISTICAL BREAKDOWN
Williams [25] bt Giorgi 3-6 6-3 6-4

WINNERS/UNFORCED ERRORS
Williams – 24/9
Giorgi – 20/14

ACES/DOUBLE FAULTS
Williams – 7/0
Giorgi – 6/6

BREAK POINTS WON
Williams – 2/8
Giorgi - 1/2

FIRST SERVE PERCENTAGE
Williams - 72
Giorgi - 53

PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Williams – 81/74
Giorgi – 77/49

TOTAL POINTS
Williams – 83
Giorgi - 67