Dundee United have named Partick Thistle boss Jackie McNamara as their new manager.
Peter Houston, 54, announced two weeks ago he would be leaving the Tannadice club at the end of the season.
However, he brought forward his departure
"It's a great opportunity. It was a big decision to leave Partick Thistle, but I feel it's one that's right for me," said McNamara.
"We've taken a risk, but we feel it's the right thing to do. I'm looking forward to the challenge.
"This is an established Scottish Premier League club with a fantastic playing squad, infrastructure and youth set-up and I cannot wait to start working with the players.
"When I spoke to the board, we shared the same vision and belief with regards to how Dundee United should progress.
"This club has very strong foundations with the majority of the first-team squad under contract beyond this summer and a very strong youth structure in place."
McNamara, 39, has guided Thistle to second place in the Scottish First Division after only being in the job for less than two years.
He took over from Ian McCall in April 2011 and with former Celtic team-mate Simon Donnelly assisting him.
His role at Firhill was his first as a manager having finished his playing days in Glasgow's west end after a lengthy career with Dunfermline, Celtic, Wolves, Aberdeen and Falkirk.
McNamara added: "I think it's one of the hardest decisions of my career, saying cheerio to the boys and finding out yesterday.
"I felt it was the right decision for myself and Simon at this stage. To leave Thistle at this stage when we're going for the league and the cup final.
"But this is a different challenge altogether. I'm very ambitious. I wish Thistle all the best - they've been great for us and I'm sure they'll go on to clinch promotion and hopefully we can come up against them next season.
"The infrastructure here, the chance to work with their youths, the training facilities and the players we've got at our disposal. They've got a great squad."
Dundee United chairman Stephen Thompson insisted the club had taken the right approach to appointing their new manager.
"It was important that we moved quickly to appoint a new manager, but it was equally important we undertook extensive homework to ensure the correct appointment," he said.
"After receiving great interest in the position, and undertaking a rigorous interview process, it was clear to the board that Jackie was the outstanding candidate to take the club forward."
McNamara had been one of the names being touted for the job, but Falkirk boss Steven Pressley had seemed the favourite to be appointed.
Former United striker Billy Dodds and ex-St Johnstone and Bristol City manager Derek McInnes were other names in the frame.
Alan Archibald takes over as interim manager at Thistle and McNamara leaves the club chasing promotion to the SPL. They are five points behind the leaders Morton, though they have two games in hand.
He joins a United set-up that faces further cuts to the playing budget as the chairman tries to reduce costs.
Dundee United play Motherwell at Fir Park in the SPL on Tuesday evening, though a pitch inspection at the Lanarkshire ground has put that match in some doubt.
The Terrors are seventh in the table and the new manager's first match will be the visit of Rangers in the fifth round of the Scottish Cup on Saturday.