OXFORD United’s blistering start did the damage, but they had to dig deep with ten men before booking their place in the Carabao Cup third round.

Newport County had won their previous six home games, but they were blown away early on.

Jason Demetriou’s own goal and a thunderbolt from Shandon Baptiste put the U’s 2-0 inside four minutes.

But the Sky Bet League Two hosts responded well and United’s defence, which had conceded four goals in their two previous away games this season, had to show plenty of resolve.

That was tested even more after the 77th minute, when Jamie Hanson received a straight red card.

A goal for Newport would have set up a grandstand finish, but instead Gavin Whyte grabbed United’s third in stoppage-time to finally kill the game.

It put United into the third round for the first time since 2002, where they will join the Premier League big guns in Thursday’s draw.

Head coach Karl Robinson had already warned he would be leaving Jamie Mackie, Marcus Browne and Ricky Holmes out to rest minor knocks.

Skipper Curtis Nelson was also left at home, as the visitors made four changes.

It included an all-new left flank, who got United off to an extraordinary start at Rodney Parade.

The visitors were ahead with their first attack of the game, in the second minute, when Baptiste broke through a challenge. He waited for Luke Garbutt on the overlap and the full back powered a cross into the six-yard box, where Demetriou haplessly sliced into his own net.

United’s hardy travelling fans were still digesting that when the second goal arrived before the game was four minutes old.

This time Baptiste went it alone. He was given space 25 yards out and the midfielder exploited it with a stunning strike to leave goalkeeper Nick Townsend grasping at thin air.

It was a dream start, which almost got even better a minute later.

Cameron Norman’s cross fell to Jon Obika, whose shot on the turn was blocked for a corner, from which Rob Dickie had a header saved.

Newport were wobbling, but steadily played their way into the game.

United had to be on their guard against Demetriou’s long throws, but the League Two underdogs showed they could play good football on the deck when given the chance.

It took time for the hosts to turn possession into chances, with Jamille Matt’s header and Tyreeq Bakinson’s long-range strike – both off target – their only meaningful efforts in the opening half-hour.

But on 31 minutes Matt must have thought he had pulled a goal back when he flicked Antoine Semenyo’s cross goalwards from point-blank range, only to see Jonathan Mitchell make an excellent save.

It was the U’s goalkeeper’s only stop of note before the break, but the half-time whistle will have come as some relief to the visitors.

Their threat largely came on the break and Townsend was fortunate in the 44th minute when he spilled Garbutt’s shot just out of Baptiste’s reach.

Both sides began the second half knowing the next goal would be crucial.

United were the first to threaten, Obika forcing a parry from Townsend after good work by Hanson five minutes after the restart.

The visitors did well to keep County at arm’s length, with Hanson and the centre halves, Dickie and John Mousinho, getting through plenty of gritty defensive work.

Mitchell was untroubled, but will have watched nervously 20 minutes from time when Bakinson’s mis-hit cross grazed his crossbar and bounced to safety.

Unted’s steady progress was disrupted 13 minutes from time, when Hanson was shown a straight red card for a late tackle on Semenyo.

It prompted a late reshuffle which left Whyte as a makeshift striker.

The Northern Irishman almost came up trumps, firing one effort wide and forcing Townsend into a save on the break.

United had another tense moment when Garbutt pulled down Padraig Amond, but the officials only opted for a booking and Dan Butler whizzed a free-kick just wide.

And the visitors promptly went up the other end to kill the game when Garbutt’s cross was flicked in by Whyte to send the County fans heading for the exits.

Newport Co (3-5-2): Townsend, Franks, Bennett, Demetriou, Forbes, Bakinson, Cooper (Marsh-Brown 61), Crofts (Sheehan 75), Butler, Matt (Amond 68), Semenyo.

Unused subs: Day, Pipe, Foulston, O’Brien.

Booked: Cooper.

Oxford Utd (4-2-3-1): Mitchell, Norman, Dickie, Mousinho, Garbutt, Hanson, Ruffels (Brannagan 75), Whyte, Smith (Long 82), Baptiste, Obika (Henry 61).

Unused subs: Stevens, Raglan, Dai, Lopes.

Booked: Garbutt, Dickie.

Sent off: Hanson.

Attendance: 2,228 (282 visitors).

Referee: Scott Duncan.