Itzhaki started his professional career with boyhood club Hapoel Ashkelon. During his first two seasons as a professional, Itzhaki won the Toto Cup Artzit twice. He was sold to Beitar Jerusalem and saw limited time under manager Eli Ohana.
With the arrival of French manager Luis Fernández in 2005, Itzhaki received more playing time and was even a first team choice over the club's leading scorer, Lior Asulin. After watching Itzhaki play, Fernández told the club to sign Itzhaki to a long term contract.
At the end of the 2005–06 season, Itzhaki attracted interest from Belgian club Racing Genk. Media reports say that he was offered a €300,000 per annum contract that includes a 20% yearly wage rise for a period no less than three seasons. Beitar was reluctant to see Itzhaki leave and they have put a price on the striker of no less than US $1,000,000. On June 25, 2006 an official bid was sent for the immediate transfer of Itzhaki but Beitar chairman Vladimir Sklar rejected the offer of USD $250,000. While Itzhaki and the club were in training in Arnhem, the Netherlands, a representative of Racing Genk showed up at the hotel with an improved offer of USD $500,000. It initially looked as if Itzhaki would be sold to the Belgian side  but he eventually signed a long term contract with Beitar. In January 2008, Itzhaki agreed a move to Racing Genk, where he signed a 3.5 year contract.
He scored his first Racing Genk goal in KV Mechelen, it is already named as the goal of the year in Belgium. After this goal he also scored against Moeskroen en Club Brugge.
On July 2008, Itzhaki returned earlier as planned to Beitar Jerusalem due to home sickness. Once back in Jerusalem he became the top scorer of the 2008–09 Israeli Premier League.
On June 9, 2010 Itzhaki signed a five-year-contract with Maccabi Tel Aviv for a transfer fee of two million USD paid to Beitar. He made his official debut for Maccabi at the home win against FK Mogren at UEFA Europa League on July 15, 2010.
On August 22, 2010 Itzhaki suffered a serious injury to his ACL against Maccabi Haifa and wasn't able to play until May 7, 2011. He made his return, replacing Maor Buzaglo in a league match against Maccabi Haifa, the same team he played against when he got injured, 32 fixtures and almost 9 months after that injury. He scored his first league goal for Maccabi by a penalty shot in the 87th minute of the last game of the season against Maccabi Netanya.
In the summer of 2012 Itzhaki was loaned to Anorthosis Famagusta. In that season Itzhaki was a vital part of team, scoring 13 league goals in 23 matches. Barak was the last (loan) transfer of Anorthosis for the season 2012-13 and was the most helpful transfer of the year, he scored 13 goals in the league and helped the team to achieve the second place.
Towards 2013–14 Itzhaki returned to Maccabi Tel Aviv, making his first game for the club since his return in the UEFA Champions League qualifying game against Győri ETO and accomplishing a great comeback to the club by socring an important away goal.Hapoel Ashkelon
Toto Cup Second Division : 2001–02, 2002–03
Israeli Premier League : 2006-07
Israel State Cup : 2008-09
Toto Cup : 2009-10
Cypriot First Division : Runner-up 2012–13
Maccabi Tel Aviv
Israeli Premier League : 2013–14, 2014–15
Israel State Cup : 2014-2015
Toto Cup : 2014-2015
2008–09 Israeli Premier League top scorer
January 2014 - UEFA's Goal of the Week