(CNN) -- Republic of Ireland striker Robbie Keane has completed a sensational return to Tottenham Hotspur on transfer deadline day, just six months after leaving the club for Premier League rivals Liverpool.
Keane was able to smile Sunday but he was watching Liverpool play Chelsea from the stands.
Keane joined Liverpool, the club he supported as a boy, for £20m ($28.5m) in July after six successful seasons with Tottenham.
However, while Liverpool have been challenging for the title, Keane has been a marginal figure at Anfield, falling out of favor with manager Rafael Benitez who has preferred to play Steven Gerrard in a more attacking role alongside Fernando Torres.
Keane regularly cut a forlorn figure on the Liverpool substitutes' bench and his departure looked a certainty when he failed to even make Benitez's squad for Sunday's 2-0 victory over Chelsea.
Tottenham manager Harry Redknapp is believed to have paid in the region of £15m (£21.4m) to secure the 28-year-old Keane's signature -- meaning he becomes the third player to return to White Hart Lane after former Spurs favorites Jermain Defoe (Portsmouth) and Pascal Chimbonda (Sunderland) also re-signed for the club during the transfer window.
"It was a difficult decision to leave Tottenham in the summer. It proved not to be the right move for me," Keane told the official Tottenham Web site.
"I know some Spurs fans will feel I let them down by leaving but I can assure them I shall be giving my all for this club -- this club has terrific fans and I want to repay them for all their support. We've got to get on and fight our way up that league table."
Tottenham chairman Daniel Levy added: "We never wanted Robbie to leave in the summer. We acknowledged the six years dedicated service he gave this club and reluctantly let him go.
"I am delighted that he has chosen to return to us. We can all recall the passion and fight he displayed during his previous seasons with us. I know he is determined to give us his full commitment."
Elsewhere, business was light on the final day of the window.
Newcastle were one of the busiest clubs, with long-serving goalkeeper Shay Given eventually completing his move away from St James' Park to join Manchester City while French winger Charles N'Zogbia has moved to Wigan Athletic with Ryan Raylor moving in the opposite direction.
As Given joined City, one player leaving the club is striker Jo, who has failed to impress since joining from CSKA Moscow in the summer for £18m ($25.6m). The Brazilian has joined Everton on loan for the remainder of the season.
Premier League strugglers Portsmouth have swooped for two Greek internationals. Experienced midfielder Angelos Basinas has joined on an 18-month contract from AEK Athens while striker Theofanis Gekas has joined on loan from Bayer Leverkusen.
Meanwhile, former French international midfielder Olivier Dacourt has also returned to the Premier League. Dacourt had successful spells with Leeds and Everton and has joined Fulham on loan from Inter Milan for the rest of the season.