(CNN) -- Rick Santorum won Tuesday's Alabama and Mississippi GOP presidential primaries, with Southern conservatives again rejecting Mitt Romney, who earlier in the day said Santorum's campaign was reaching a "desperate end." Newt Gingrich, the native Southerner who was under the most pressure to take both states, was fighting with Romney for second place in both contests and pitched that as part of his reason to continue campaigning through the GOP convention. In Alabama, with 99% of the vote counted, Santorum led with 35%, followed by Gingrich at 29%, Romney at 29% and Ron Paul at 5%. With 99% of the vote counted in Mississippi, Santorum had 33%. Gingrich was at 31%, Romney at 30% and Paul at 4%. Results of caucuses in Hawaii and American Samoa had yet to come in. "We did it again," Santorum told supporters Tuesday night in Lafayette, Louisiana, which will hold a GOP primary on March 24. Santorum, whose Alabama and Mississippi victories give him 10 wins to Romney's 16, poked at the front-runner as he reiterated his stance that he is the viable conservative alternative to the former Massachusetts governor. "People (said), 'You're being outspent (by Romney),' and everybody's talking about all the (delegate) math, and that his race is inevitable. Well, for someone who thinks this race is inevitable, (Romney) has spent a whole lot of money against me for being inevitable," Santorum told supporters. Earlier in the day, Romney, who still holds a large overall delegate lead, said Santorum's campaign was trying to resuscitate a losing effort. "Sen. Santorum is at the desperate end of his campaign, and trying in some way to boost his prospects," Romney said on CNN's "The Situation Room." As news was breaking of Santorum's win in Alabama, Santorum communications director Hogan Gridley replied to Romney's statement, saying, "It's just the beginning." Santorum, a former senator from Pennsylvania, was coming off a big win in Kansas on Saturday and has given himself a bigger boost in the battle to be the conservative alternative to Romney by beating Gingrich in Alabama and Mississippi, in the Georgia native's home turf in the South. The wins are somewhat of a surprise, because polls released Monday showed Santorum running 8 to 10 points behind Romney and Gingrich in the two states. Still, because Alabama's 47 delegates and Mississippi's 37 delegates will be awarded proportionally, Romney appeared to maintain his delegate lead and may add to it after more moderate Hawaii and American Samoa are counted. A CNN delegate estimate late Tuesday night showed Romney with a 480-234 lead over Santorum, giving him the same 246-delegate margin that CNN estimated he had before Tuesday's results. The estimate had Gingrich at 139 delegates and Paul at 66. The number of delegates needed to clinch the nomination is 1,144. Gingrich, speaking to supporters in Birmingham, Alabama, focused on the amount of votes that Romney didn't get, and said that "the elite media's effort to convince the nation that Mitt Romney is inevitable just collapsed." "The fact is that in both states, the conservative candidates got nearly 70% of the vote, and if you're the front-runner and you keep coming in third, you're not much of a front runner," Gingrich said. "And frankly I do not believe that a Massachusetts moderate who created Romneycare as the forerunner of Obamneycare is going to be in a position to win any debates this fall, and that is part of the reason I've insisted in staying in this race." Gingrich said he still had time to persuasively argue that he is the conservative who should go against President Barack Obama in the fall. The former House speaker has won contests in South Carolina and Georgia, which he represented in Congress for two decades, but has finished third or worse in most contests outside the region and campaigned intensively in Alabama and Mississippi over the last week. Romney's campaign has been holding up its large lead in delegates as a reason for Gingrich and Santorum to get out of the race. But Romney, who flew to New York on Tuesday ahead of a fundraiser and did not plan to address supporters Tuesday night, wouldn't have turned down a win in a region dominated by social conservatives, who have been hesitant to support his candidacy. Eric Fehrnstrom, a Romney campaign senior adviser, said the campaign met its goal of taking roughly one-third of the Mississippi and Alabama delegates. "Once the dust clears, you'll be able to look and see that there really will be no ground that our opponents have made up against Mitt Romney," Fehrnstrom said Tuesday night. "And as you look at the upcoming contests on the calendar, there are no opportunities for them to have significant wins that allow them to accumulate large numbers of delegates so that they can close that gap with Mitt Romney."