Just 24 hours into the Wimbledon championships, it is becoming increasingly obvious that Roger Federer's bid for a record-equalling sixth successive title will not be seriously tested until the semi-finals.

That is when the World No1 is due to meet third seed Novak Djokovic but even the popular Serb may be removed from the draw if Marit Safin remembers he is a Grand Slam champion.

Djokovic, who defeated Michael Berrer 7-5, 2-6, 6-3, 6-0 now faces Safin, the former US Open and Australian Open champion, tomorrow in one of the most mouth-watering second round matches ever scheduled at the tournament.

Federer was odds on to ease his way through the early rounds even before potential third-round opponent Gael Monfils withdrew with a shoulder injury, ending hopes of a repeat of their French Open semi-final clash

Now, only former champion Lleyton Hewitt and his dodgy hip offer real danger to Federer, who easily accounted for close friend Dominik Hrbarty, 6-3, 6-2, 6-2 in yesterday's first round.

Next up tomorrow is Robin Soderling, the big-serving Swede who is being talked up as a possible problem for Federer, although this is difficult to believe given the Swiss superstar has a 6-0 career record against the World No41.

Even Federer is "bigging up" Soderling's tennis game, although this appears more in the hope of being given a real work out in the second round than suggesting his sixth title is under threat.

If Federer does make it six-in-a-row he will equal the record of Warwickshire's William Renshaw, who achieved that feat in 1886 when you only had to win one match in the challenge round to retain the title. You could make a genuine argument for Federer to enjoy similar treatment at Wimbledon as he has now amassed 60 consecutive wins on grass (at Halle and the All England Club) and hasn't dropped serve on the surface this year.

Arriving on court yesterday resplendent in a cardigan that Renshaw could well have sported, Federer exudes a confidence at SW19 that he never attains at the other three Slams in Melbourne, Paris and New York. Here is a man born to play tennis on grass and the feel of the surface beneath tennis shoes that are produced specifically for him is surely a comfort in times of distress.

Having been thrashed in straight sets by Rafael Nadal in the French Open, Federer couldn't wait to get to Wimbledon and now it's just a question of exactly how well he negotiates the route to another final.

But while the Swiss has his eyes on a sixth prize, he will give Soderling due respect and said: "I think the next round will be a difficult match and I will definitely not underestimate him. I think grass really suits his game because he's got a great serve.

"Getting through the first round is a key as I have an extra day of practice. Robin is a dangerous player, because on one particular day he can play top 10 tennis with that great serve and aggressive baseline game. He gave up against me in Miami and those are just signs, sometimes, of being a little weak mentally. But nevertheless, it's not a whole lot of fun playing against him in the second round of Wimbledon."

Djokovic had a real battle on centre court last night, against Germany's Berrer, a burly left hander, before emerging a four-set winner.

While Wimbledon is Federer's second home, the tournament is a work in progress for the Serbian No3 seed who has improved his performances on the lawns every year he has played. A semifinal against Rafael Nadal last year saw him retire due to blisters and he finished the year strongly by reaching the final of the US Open where he lost to Federer.

The Australian Open saw the 21-yearold become a Grand Slam champion for the first time and that break-through proved that Djokovic could really threaten Federer and Nadal and that there was now a trio of potential Slam winners on the men's tour.

Djokovic, like Federer, credits Wimbledon with inspiring him to become a world-class player - particularly his fond memories of the last man to completely dominate SW19.

He said: "I still have a picture in my head of Pete Sampras holding the Wimbledon trophy. So this is the image that stayed all the way throughout my career and which motivated me to become a professional tennis player."

Becoming a serious contender at Slams has changed Djokovic's status in the sport and although he remains the big joker in the men's locker room, he knows the Australian title has made him a serious draw for the fans.

"It feels nice when the people come up to you and greet you in a positive way," he added. "Of course, not everybody likes you, but most of the people that come up to me just congratulate me or just show appreciation for what I have done. It feels great when you get recognised in the streets or in the tennis site."

That is also true of Safin and the tall Russian with the volatile temper set up the meeting with Djokovic with a 6-3, 6-2, 7-5 victory over Italy's Fabio Fognini.

Safin looked ready to dominate the sport when he won the US Open in 2000 but it took him five years to reach that level again with triumph in Australia and his star recently has flickered rather than shone.

Yet while he famously cites the lawns of Wimbledon as his least favourite surface, he at least has the ability to upset Djokovic's right to meet Federer in the semifinals.