When British boxing fans flock to Las Vegas on Saturday  to watch Joe Calzaghe, BBC Sports Personality of the Year, fight Bernard Hopkins for the world light-heavyweight title, one winner is assured: the sports travel industry.

Operators predict that 25,000 fans will spur on the "Pride of Wales", topping the 20,000 Mancunians who witnessed their local hero Ricky Hatton's world welterweight title fight in LasVegas last December.

Such a passionate following underlines the growth of the sports travel industry, which has spawned a host of businesses combining tickets for high-profile sporting events with flights and accommodation.

Boxing is the latest sport to be caught up in the demand for events-based tourism. Cricket led the way in the mid-1990s when TV coverage of England's overseas tours prompted die-hard fans to marry their sporting obsession with an opportunity toescape harsh winters.

Estimates of the number of England cricket fans in New Zealand for their team's recent tour are about 7,500 - nothing like the 45,000 who travelled to Australia for the 2006-07 Ashes series, but enough to match the number of locals in New Zealand's sparsely attended venues.

Ardent fans

But sports tour operators are licking their lips at the British Lions' tour next year to South Africa, likely to tempt 55,000 rugby lovers - about 20,000 more than followed the Lions on the ill-fated New Zealand tour three years ago.

While the distance encourages most ardent fans to plan 17- or 18-night visits, tour operators are packaging quick-turnaround, business-class trips, expecting some to sleep on the aircraft on the way out to South Africa, take in a Lions Test and fly straight back home. The time zones are similar.

Nigel Currie, of the sports marketing agency Brand-Rapport, says sports travel has grown at an astonishing rate since the days when a few hundred football fans used to endure a 12-hour round trip to the continent for a midweek European fixture in order to avoid being absent from work.

Now, with three English teams - Chelsea, Liverpool and Manchester United - in the Champions League semifinals - guaranteeing that at least one will reach the final - fans are eyeing packages to Moscow, where it is being hosted.

"People are looking for an excuse for a holiday," said Currie. "And the sports bodies are squeezing tour itineraries to accommodate them, such as scheduling back-to-back Test matches, or staging rugby internationals one week apart."

Long-standing specialist tour businesses are finding their ticket allocations reduced as sports bodies distribute them across a wider number of operators.

"We've got a lot more competition because it's a successful niche area in the travel business," said John Hall of Gullivers Sports Travel.

The biggest impact on the market is likely to be from mainstream tour operators such as Thomas Cook. With their high-street presence, the big operators pose a challenge to seasoned, specialist sports tour operators reliant on online traffic for their business.

Thomas Cook got into sports travel by accident, helping Manchester City and its fans on a fleeting foray into Europe after it became the Premier League club's shirt sponsor.

Now it manages the travel arrangements of clubs such as Arsenal, Chelsea, Everton and Tottenham Hotspur, and their fans. It is one of the official tour operators for the Lions' 2009 tour, and the official tour op-erator for the Calzaghe fight.

"People are being much more ambitious with their travel," said Danny Talbot of Thomas Cook Sport.

"It's a time-poor, rich money market. You can develop some very keen prices for some of these tournaments."

Boxing is but one example where sporting success influences the market. Hall is confident that Lewis Hamilton's exploits are going to lure more UK Formula One fans around some of the world's Grand Prix circuits.

Thus far, the trend in sports travel has been a fairly male-dominated affair. Talbot says there is growing interest from women, particularly in rugby and cricket, which offer the possibility of more exotic destinations.