Santorum has won the primary but Mitt Romney still remains the favourite to become Republican nominee.

Rick Santorum won the Louisiana Republican presidential primary on Saturday, beating front-runner Mitt Romney in the race to challenge President Barack Obama, The Guardian daily reported Sunday.

Although the victory gives Santorum bragging rights and at least eight more delegates, it does not change the overall dynamics of the race; the former Pennsylvania senator still dramatically lags behind Romney in the hunt for delegates to the Republican's summertime nominating convention.

Even so, Santorum's win underscores a pattern in the drawn-out race.

He has tended to win in the states of Tennessee, Mississippi and Alabama.

Neither candidate was in the state as Louisiana Republicans weighed in. Nor was former House Speaker Newt Gingrich, who was trailing in Louisiana. With half the precincts counted, Santorum had 49% to 26% for Romney. Gingrich was far back at 17%, followed by Ron Paul with 6%.

In an unmistakable jab at Romney, Santorum added: "Don't make the mistake that Republicans made in 1976. Don't nominate the moderate. When you do, we lose." It was a reference to Ronald Reagan losing the 1976 Republican nomination to incumbent

The bad economy was the top issue for Louisiana voters. Most were gloomy about prospects for a recovery, saying they felt the economy was getting worse instead of better.

Romney is far ahead in the delegate count and on pace to reach the necessary 1,144 delegates before the party's convention in August.

With the Louisiana results, Romney leads the overall race for delegates with 563, followed by Santorum with 271, Newt Gingrich with 135 and Ron Paul with 50.

Santorum badly needed a rebound after a decisive Illinois loss to Romney earlier in the week that moved party stalwarts to rally around the front-runner. Many urged Santorum and Gingrich to drop out of the race.

Both refused, and campaigned aggressively in Louisiana in hopes that a victory there would justify them staying in despite Republican worries that the long nomination fight could hurt the party's chances against Obama.

The next key fight comes 3 April in Wisconsin. Romney's campaign is airing TV ads in the state, and his super PAC allies have plowed more than $2 million into TV advertising there.

Also voting 3 April are Maryland and the District of Columbia. There are 95 delegates combined at stake in the three contests.