Widnes coach Denis Betts admits his team are still struggling to rid themselves of the bridesmaid's tag after suffering an agonising 20-18 defeat in their Ladbrokes Challenge Cup quarter-final at Warrington.

The Vikings led 12-6 thanks to tries from Joe Mellor and Matt Whitley and, after falling 18-12 behind, demonstrated tenacity to fight back and level the scores with Charly Runciman's 74th-minute try, only to concede a late penalty.

"It was a good cup-tie," Betts said. "You want these kind of games, where you're on the edge of your seat.

"We had lots of energy and enthusiasm and, although we're not as sharp with the ball as we could be, I wanted us to be able to defend and we did, we scrambled really well.

"It could have gone either way but we're just coming out on the wrong side. They are fine margins in the game. We were competitive against a side that has been sitting at the top of the table.

"We're a good side, we're just an inch off with a couple of things. We jus t seem to be the bridesmaids and that needs to change. Things will fall our way if we keep working hard."

Warrington scored tries through Kevin Penny, Jack Hughes and Brad Dwyer but were indebted to Kurt Gidley's second penalty seven minutes from the end as they sealed a fifth successive semi-final appearance.

It was a touch of deja vu with Gidley kicking a late penalty to earn his side a 20-18 Super League win over Catalans Dragons a week ago.

"We're not silky smooth at the moment and we're probably taking a few more penalties than we normally would," said Wolves coach Tony Smith. "We thought points on the board would be the right way to go.

"The game had a bit of everything and kept people on the edge of their seats . We weren't quite at our best by any means, but I'd put a lot of that down to Widnes. T hey came here for a game and we knew they would.

"My boys tried their hearts out. It wasn't a classic or a pretty game, it was a grafting game, a war of attrition, and the effort from both teams was enormous.

"There are areas we need to improve - I thought our kick-chase at the end was pretty average - but it's good when you've got the desire to win when you're not at your best."

Warrington might have wrapped up the game during a period of pressure on the Widnes line early in the second half had centre Ben Currie not been denied a try following a charge for the line.

"I thought that was the big call," Smith said. "I don't know if anybody else saw a knock-on, we couldn't find one."