[12] On 21 March 2001, Powell was sent–off for the second time that season, in a 2–1 win over Southend United,[11] which saw Brentford go through to the LDV Final following a 4–2 on aggregate.
[15] Powell then captained Brentford for the first time in his career following the absence of Paul Evans, as the club lost 1–0 against Northampton Town.
[21][22] Powell made his Crystal Palace debut in the opening game of the season against Preston North End, starting and scoring the first goal, in a 2–1 win.
[28] While on the sidelines, Powell was close to joining Palace's Division One rivals, Reading, but the transfer move broke down, citing a failed medical, as well as, manager Iain Dowie's desire to keep him.
[30] Powell made his first appearance from injury on 14 May 2004, where he came on as a late substitute in a 3–2 first-leg Play-off semi-final win over Sunderland.
[35] Upon returning to Palace, Powell made his first Premier League appearance, where he played the whole game, in a 2–0 win over Aston Villa on 3 January 2005.
[38] Powell made his Southampton debut, where he played the whole game in a centre–back partnership with Tomasz Hajto, in a 0–0 draw against Wolverhampton Wanderers.
[39] He then helped the Saints keep three clean sheets during August against Sheffield Wednesday, Norwich City and Crewe Alexandra.
[45] He did not make his return to the first team until 6 January 2007, where he played the whole game, in a 2–0 win over Torquay United in the first round of the FA Cup.
[47] Once again, Powell helped the side keep two clean sheets in a row against Wolverhampton Wanderers and Luton Town between 31 March 2007 and 7 April 2007.
[50] His suspension came after he was sent–off for violent conduct after reacting angrily to a heavy challenge from Phil Mulryne, in the club's win at AFC Bournemouth the previous month.
[52] After being sidelined on three separate occasions throughout January,[55] Powell scored his second goal for the club with a first minute tap in from Adam Hammill's cross in a 3–2 home defeat to Queens Park Rangers.
[52] After three years of failing to establish himself in the first team due to a run of minor injuries, returning chairman Rupert Lowe decided not to renew Powell's contract.
[57] He trained with Charlton Athletic whilst searching for a club and was handed a trial at Derby County in November 2008.
[58] On 21 November 2008, Powell signed an initial two-month contract for Derby,[59] and made his debut in the 2–0 defeat to Ipswich Town a day later.
[65] He managed only a handful of appearances before being sent–off on 14 April 2009, in a 1–0 win over Bournemouth following an altercation with teammate Karleigh Osborne.
[70] Then, on 3 October 2009, Powell played a vital role when he set up the only goal of the game, in a 1–0 win over Brighton & Hove Albion.
[73] In January 2012, Hampton & Richmond Borough Chairman Steve McPherson claimed that Powell was close to making a comeback with the club.
[75] He made his second debut for the club the next day coming off the bench at half time in a 2–2 draw away to Havant & Waterlooville.
[76] In April 2013, Powell and first-team coach Paul Barry took charge of Hampton & Richmond Borough, now in the National League South, on a caretaker basis until the end of the season after manager Mark Harper resigned his position.
[82] However, a poor start to the 2014–15 season saw Powell sacked along with Barry after Hampton & Richmond lost 3–2 to VCD Athletic in the FA Cup qualifying round on 13 September 2014.
[85] In March 2023, after Roy Hodgson returned as manager with Paddy McCarthy as his assistant, Powell was appointed as head-coach of the under-21 team.