LONDON - WHEN she smiles, Jelena Jankovic plays her best tennis.

The bubbly sixth-seeded Serb had plenty to be happy about after booking a place in the Wimbledon second round with a 6-4 7-6 victory over Germany's Julia Goerges on Tuesday but said she still needed to relax more on court.

'The most important thing is to just enjoy my tennis, find that smile on the court when I'm competing, and play loose no matter what,' the former world number one told a news conference.

'Just go out there and have fun. And then that's the time when I play great tennis. When I'm disappointed and frustrated with myself, with the mistakes I make, then that is not good for me.' Jankovic has admitted her confidence has taken a knock after a below-par season in which she has slipped from top spot at the end of last year to sixth in the world rankings.

She demonstrated the green shoots of recovery on Tuesday when she pulled herself out of danger when trailing 5-2 in the second set despite suffering with sore feet.

'I showed my fighting spirit at 5-2. I didn't give up. I just fought every point,' said Jankovic, who had to call a medical timeout at the end of the first set because of blisters and a broken toenail.

'I hung in there, even if you don't play your best tennis, be in the match, you know, and always believe you can win,' she said.

'I think I'm more enthusiastic. And I'm more positive, as well. You have to look on the bright side, as well.' Compatriot Ana Ivanovic advanced to the next round after a nail-biting 5-7 6-2 8-6 victory over Czech Lucie Hradecka later in the day, and 2008 Australian Open champion Novak Djokovic went safely through to the men's second round on Monday.

Asked why Serbs were enjoying such a successful spell in sport, Jankovic said: 'We're just a talented nation. I don't know how to explain it.

'We have that hunger. We are big fighters. We want to be the best that we can. We don't really accept second places. We want to be the first. So I think with this kind of mentality, that's why we are quite successful in sports.' -- REUTERS