Although he’s still a long way from crawling, 7-week-old Tim Montgomery already has had a huge impact on the sprinting events at the track and field world championships that start Saturday in a Paris suburb.

His birth has left the field wide open in two of the signature events of the nine-day meet — the women’s and men’s 100 meters.

Tim’s mother — Marion Jones, defending champ in the 200 and Olympic champ in the 100 — is taking time off after giving birth June 28. And his father — Tim Montgomery, the world record-holder in the 100 — has struggled on the track after five weeks of paternity leave.

“He wasn’t plan-ned, but sometimes the greatest things in life aren’t planned,” Jones said. “He’s really been a blessing in our lives. We’re really happy with the whole situation.

“What is the world championships when you can bring a life into this world?”

Montgomery, who skipped much of the European track circuit while returning to Raleigh, N.C., to change diapers and be with Jones and their infant son, has been practically crawling himself since returning to Europe two weeks ago.

Montgomery, who set the world record of 9.78 seconds last year in Paris, finished sixth in 10.37 at a meet in Stockholm and failed to make the final of a race in London.

“It’s been crazy, I’d been jumping up and down, changing diapers, watching Marion train, training myself,” Montgomery said after the Stockholm race.

Montgomery’s vulnerability and the season-long struggles of three-time defending champion Maurice Greene have opened the door for sprinters such as European champion Dwain Chambers of Britain and U.S. champion Bernard Williams — who beat Montgomery in June to win his national title.

Williams won an international race July 4 on the same Stade de France track that will host the world championships.

Both of the women’s sprints are up for grabs as well.

Zhanna Block of Ukraine edged Jones to win the 100 at the 2001 world championships in Edmonton, Alberta, but has struggled this season. U.S. champion Kelli White and Chandra Sturrup of the Bahamas are now the favorites.

In the 200, the absence of Jones could be tempered by the emergence of teen sensation Allyson Felix, who like Jones grew up in the Los Angeles area. Felix, 17, has the world’s fastest time of 22.11 this year.

It’s not her first trip to Paris, but this time Felix hopes to take home a medal instead of souvenirs.

“I went sightseeing one day on the last trip. I saw the famous shopping street and the Eiffel Tower. We tried to cram everything into one day,” she said. “I’m kind of focused now.”

Coming a year before the Athens Olympics, these world championships will be a preview of the 2004 Games and a chance for some younger performers to stake their claims as favorites for next summer.

The meet will be held in the 70,000-seat Stade de France that also hosted the 1998 World Cup soccer final.