Laura Robson stuns Petra Kvitova at the Australian Open in thrilling match

British number two comes through remarkable match in Melbourne

Laura Robson was given higher billing than Andy Murray at the Australian Open here today and the 18-year-old from Wimbledon rewarded the tournament organisers' faith with a stunning performance.

Robson, who beat two Grand Slam champions in Kim Clijsters and Li Na at last year's US Open, claimed the scalp of a third when she beat Petra Kvitova, the winner at Wimbledon two years ago, 2-6, 6-3, 11-9.

Robson featured in the second match of the night session in Rod Laver Arena, the main show court at Melbourne Park, after Murray had played in the heat of a scorching day in Hisense Arena, the second stadium.

Murray was much too good for Portugal's Joao Sousa, winning 6-2, 6-2, 6-4 in just an hour and 41 minutes to earn a third-round meeting with Lithuania's Ricardas Berankis, but Robson went on to upstage her Olympic mixed doubles partner. She now meets Sloane Stephens, of the United States, in the third round.

The temperature had topped 40C in the afternoon and was still 30C when Robson completed her victory half an hour after midnight. Kvitova can struggle in the heat and Robson took full advantage.

Robson, nevertheless, had made the worst start imaginable, serving two double faults and losing the first game to love. When Kvitova started the next game with an ace the signs looked ominous, but Robson responded well and broke back immediately.

The match quickly developed into a slugging contest between two of the game's big hitters. The two left-handers have similar games, based around the power of their ground strokes and the potency of their serves. With both women going for their shots, lengthy rallies were as rare as rainfall in an Australian summer.

Kvitova won the first set with something to spare, despite hitting seven double faults. Robson lost five games in a row at the end of the opener, but the world No 53 came back superbly in the second, breaking twice in a row to take a 5-1 lead and holding firm after the world No 8 threatened to launch a comeback.

However, just when Robson appeared to have taken the initiative Kvitova seized it back, winning the first three games of the decider. Robson rallied and broke to lead 6-5, only to fail to serve out for the match. When the second chance came, however, she made no mistake, serving out to love to claim victory after nearly three hours.

Earlier in the day Murray clearly had no intention of being on court in the stifling heat any longer than necessary. Hisense Arena used to be a velodrome and Bradley Wiggins could hardly have covered the ground more effectively than the world No 3, who went on the attack from the start.

Sousa was outclassed in every department. Murray, striking the ball well from both flanks, immediately had his opponent on the back foot. The Scot broke serve five times, while Sousa did not force a single break point.

"I've played in worse conditions, but it was still very hot," Murray said afterwards. "When the sun came out, it was extremely hot. When it wasn't, it was fine."

From 1-1 in the first set Murray made two successive breaks of serve to take a hold on the match. The first set was secured in 31 minutes and Murray raced into a 4-0 lead in the second before Sousa held twice to bring some respectability to the scoreline. Murray broke in the opening game of the third set and served out for the match.

Murray's next opponent, 22-year-old Berankis, will be best remembered in some quarters for his Davis Cup heroics in 2010 when Britain visited Lithuania. Berankis won both his singles rubbers to inflict the most embarrassing defeat in Britain's history.

Currently world No 110, Berankis broke into the top 100 three years ago, but his last two seasons have been disrupted by a groin injury. In winning three matches in qualifying and two in the main draw Berankis has dropped only one set. He claimed his biggest scalp so far with a 6-2, 6-3, 6-1 victory today over Germany's Florian Mayer, the world No 28.