The Liberal Democrats have recorded two stunning victories capturing their top target seat of Cardiff Central from Labour and Ceredigion from Plaid Cymru.
Jenny Willott came within 659 votes of winning in 2001
Jenny Willott turned a Labour majority of 659 in the 2001 election to one of 5593 for the Lib Dems in Cardiff Central.
In Ceredigion, Mark Williams narrowly triumphed over Plaid Cymru's Simon Thomas by 219 votes.
The Lib Dems' Welsh leader Lembit Ípik called it a "fantastic night".
Mark Williams said the voters had delivered is a simple message. "Here in Ceredigion, across Wales and in Britain as a whole, it's clear that the Liberal Democrats are the real alternative.
"The residents of Ceredigion have embraced the positive message of Charles Kennedy and the Liberal Democrats and come home to the Liberal Democrats.
"It has been an amazing campaign and for us Liberal Democrats it has resulted in an amazing result".
Mark Williams gained a small majority over Plaid's Simon Thomas
However, Plaid's defeated Simon Thomas said: "We kept up our vote but the Lib Dems managed to get votes from other people like students and people who had had enough of Michael Howard."
Jenny Willott had also contested Cardiff Central in the 2001 general election and the party had campaigned hard with Charles Kennedy's help, hoping to capitalise on the vote of thousands of students living in the constituency.
She defeated the former Welsh Office minister Jon Owen Jones, who had represented the seat since 1992.
The city centre constituency was the Lib Dems' top target seat in Wales and fourth in the UK.
"We never stopped campaigning," said Ms Willott.
"We have been building up our strength across the constituency. It was combination of different things, like winning control of the council (in Cardiff).
Labour's Jon Owen Jones had represented Cardiff Central for 13 years
"It was not just one issue that won this for us. It was a combination of things, the NHS, local income tax, student fees and so on."
Labour's Jon Owen Jones held the seat with a majority of under 700 in 2001.
Lembit Ípik, leader of the Welsh Lib Dems, said: "We started the night with two MPs, and we finish it with four - a 100% increase.
"Jenny Willott managed to build a very healthy majority, and Mark Williams has pulled off the result of the night in Ceredigion.
"I've been telling anyone who will listen that Ceredigion was coming home for two weeks."