Republican Sen. Ted Cruz of Texas won reelection Tuesday night, holding off a hard fought challenge from Democratic upstart Beto O'Rourke.

Early results showed O'Rourke running neck and neck with Cruz but the incumbent senator managed to pull off a victory.

With 79 percent of the vote in, Cruz was leading O'Rourke 51 percent to 48.4 percent.

O'Rourke gave an impassioned concession speech to screaming fans where he told his hometown: 'El Paso, I love you so much' and then dropped the f-bomb as some networks carried his speech live.

'I want to thank this amazing campaign of people,' he said. 'All people all the time, all the time, in every single part of Texas, all of you, showing the country how you do this. I'm so f****** proud of you guys.'

MSNBC was airing his speech when the obscenity occurred.

'Sorry for the F-bomb,' anchor Brian Williams said. 'We have no control of what's in the concession speeches.'

Beto O'Rourke dropped the f-bomb in his concession speech after his loss to Ted Cruz

O'Rourke with his wife Amy

Sen. Ted Cruz managed to hold a challenge from Beto O'Rourke

Cruz has led in the polls throughout their matchup -but O'Rourke gave him enough of a political scare he campaigned like a man who was afraid he'll lose: holding some 50 rallies in the past six weeks and bringing in his former rival for the 2016 presidential nomination, Donald Trump.

Democrats held on to faint hopes that record high early voting numbers - more Texans voted early in 2018 than voted in total in 2014 - would give the result they desperately hoped for in the most expensive Senate race in the 2018 midterms.

But even a loss for O'Rourke could be a win.

The two-term Congressman from the Texas-Mexico border has exploded on to the national scene. His extensive use of social media - even doing Facebook Lives in his car as he drives between campaign rallies and orders from Whataburger - has endeared his aw-shucks demeanor to Democrats across America.

He set a Senate fundraising record when he brought in $38 million in the third quarter - giving him a war chest presidential candidates would envy - but, more importantly, he's breathed new life into the Democratic Party in Texas, a state they have long hoped to turn blue thanks to its rising Latino population.

All this has resulted in O'Rouke being named as a possible 2020 presidential candidate, which he denies interest in, keeping a laser-like focus on his Senate bid while still maintaining his laid back attitude.

More Texans voted early in 2018 than voted in total for 2014, which O'Rourke has claimed would help him.

'I think the more people that show up, the better we do,' O'Rourke told CBS' '60 Minutes' on Sunday night.

'The people who are fired up right now are fired up to do something great for this country. That's my sense. I don't have a pollster, so I can't quantify this assumption for you. But the turnout that we're seeing is already off the charts,' he added.

Beto O'Rourke poses for a photo with his family outside of a polling place before voting; his wife, Amy and three kids - Ulysses, 11, Molly, 10, and Henry, 7,

Cruz brought in President Trump to campaign for him

Nearly 4.9 million votes were cast in the 30 most populous counties in Texas when early voting ended Friday night, the Texas Secretary of State's Office reported.

That tops the total statewide turnout from 2014 by 157,000 votes.

The top 30 counties are home to about 80 percent of all Texans.

But Cruz argued the math is in his favor.

Republicans in Texas hold the governor's mansion, majorities in both chambers of the state legislature, both U.S. Senate seats, and, of the 36 congressional districts in the state only 11 are held by Democrats.

A Democrat in Texas hasn't won statewide election Texas since 1994.

'If you look at the dynamics, we've got numbers on our side. There are a lot more conservatives than there are liberals. What the O'Rourke campaign has had on their side is intensity. The liberals who are in Texas are really, really mad. They hate President Trump. That anger is dangerous. I mean, that anger is mobilizing. It means they're gonna show up no matter what. As I've said, they'll crawl over broken glass to show up,' Cruz told '60 Minutes.'

He conceded: 'Intensity is always potent. Intensity turns people out at the polls.'

Cruz wrapped up his campaign on Monday with a final stop at the spot where he officially launched his re-election bid: a Houston-area honky-tonk called the Redneck Country Club.

'Every liberal in the state of Texas are going to show up and vote,' he warned the packed hall.

'We are going to win this race,' he added. 'And let me tell you how I know that: Because this is Texas. And in Texas it is in our DNA, it is in our blood to defend liberty.'

Cruz wrapped up his campaign with a final stop at the spot where he officially launched his re-election bid: a Houston-area honky-tonk called the Redneck Country Club.

The media mobs O'Rourke after he voted Tuesday morning

Democratic Senate candidate Beto O'Rourke voted in El Paso Tuesday morning with his wife, Amy, three kids - Ulysses, 11, Molly, 10, and Henry, 7, and members of the media in tow

O'Rourke has made extensive use of social media during his upstart campaign - conducting Facebook Live videos from his car as he drives to campaign stops - while Cruz has used the more traditional approach of rallies and retail politics.

He raised an record breaking $38 million in the third quarter of his Senate campaign.

'I think the way in which we are running it, without PACs, without special interests, without pollsters, without consultants, going to every county, all 254. At this really divided moment, everybody, knowing that they're invited to be part of this,' O'Rourke told CBS.

No big name Democrats - like former President Barack Obama or former Vice President Joe Biden - have appeared for O'Rourke.

'I'm not distancing myself. But I don't want anyone coming in from the outside. I want the people of Texas to decide this on, on their own terms,' O'Rourke told CBS News.

Cruz brought in the big GOP - President Donald Trump - to campaign for him.

The president slammed O'Rourke during the Oct. 22 rally and praised Cruz, his one time rival for the Republican presidential nomination.

Trump called O'Rourke a 'stone-cold phony' as he mocked him for campaigning on his nickname Beto instead of his given name 'Robert'.

'And he pretends to be a moderate, but he's actually a radical, open-borders left-winger,' Trump contended, painting him as a proponent of a 'socialist take-over of health care' who wants to 'take away your guns'.