Following an end-of-season tour of Australia during which Osgood scored 12 times in eight games, the centre-forward's next senior match was the September 22 1965 4-1 victory over AS Roma in the Inter-City Fairs Cup (a violent encounter dubbed "the Battle of the Bridge"). A run in the league followed, bringing seven goals, including one involving a 60-yard run past a trail of Burnley players.
The teenager was soon hailed as a possible late call-up for Alf Ramsey's 1966 World Cup squad, having been included in the original 40-man squad announced in April 1966, but he was not included in the final 22. He was taken to the hearts of the Chelsea faithful, who nicknamed him "the Wizard of Os".
A broken leg suffered in a challenge by Blackpool's Emlyn Hughes in the League Cup on October 6 1966 seriously curtailed his progress, and he missed Chelsea's first-ever Wembley FA Cup final on May 20 1967. Without him the Blues lost to Tottenham Hotspur 1-2.
It was a major disappointment for this big-stage player yet 'Ossie' returned from the injury an equally graceful - if tougher - player. His vision and physical presence were recognised by new manager Dave Sexton playing him often as a midfielder, but it is as a goalscoring centre-forward that he is best remembered.
In total, Osgood made 380 appearances for The Blues, scoring 150 goals. He was one of only nine players to score in every round of the FA Cup (and, to date, the last to do so), helping Chelsea to victory in a replayed final against Leeds United in 1970. He scored Chelsea's equaliser in the second game at Old Trafford with a diving header from Charlie Cooke's chipped pass twelve minutes from full time; his side eventually won 2-1.
In 1971, Osgood was part of the Chelsea team which lifted the European Cup Winners' Cup, defeating Real Madrid 2-1 in Athens, where he scored Chelsea's second, decisive, goal. In 1972, he scored for Chelsea in a major cup final for the third consecutive year - this time the League Cup - though they lost 1-2 to Stoke City. Chelsea declined as a major force thereafter, but Osgood continued to score regularly; his volley from outside the area against Arsenal in the FA Cup quarter-final was voted goal of the season in 1972-73.
Osgood returned to Chelsea in December 1978 following a disappointing stint in the United States with the Philadelphia Fury, where he scored only 1 goal in 23 matches for a team which also included Alan Ball and Johnny Giles. On his return to Stamford Bridge, the club were in deep decline and facing a relegation battle. He again scored on his debut to put his team ahead, though Chelsea still lost 7-2 to Middlesbrough. He stayed with the club for the rest of the season before retiring in December 1979.
Osgood was commonly called "Ossie" and also earned the nickname "The King of Stamford Bridge" due to his exceptional skills as a player as well as his personality and status. Osgood was known as a charming and confident man, and on the pitch he had the slight touch of arrogance found in great football players. Few things summarise his status as well as a T-shirt worn by Raquel Welch, one of the greatest movie stars of the era. The T-shirt simply said "I scored with Osgood". To this day, Peter Osgood's status in the London club is unrivalled.
His autobiography 'Ossie - King of Stamford Bridge' written with Martin Knight and Martin King was released in 2003 and in 2004 Osgood appeared in a cameo role in the British film The Football Factory.
Prior to his death on March 1 2006 following a heart attack at a family funeral, he was involved in football related media work and was well known on the after dinner speaker circuit. Three weeks before his death he had enjoyed a standing ovation when presented to the Stamford Bridge crowd at half-time of a match.
At Chelsea's first home game after Osgood's death, against local rivals Tottenham, there were many tributes as well as a minute's applause. Many of his former team-mates were in attendance and the matchday programme ran a tribute to him. The atmosphere was one of joyous remembrance, and in keeping with this theme Chelsea ran out 2-1 winners after a closely contested match, thanks to an excellent last minute goal by William Gallas.
In a memorial service on Sunday, October 1, 2006, Peter Osgood's ashes were laid to rest under the penalty spot at the Shed End of Stamford Bridge. Over 2500 fans attended the memorial service and they were joined by former managers, chairmen, players, colleagues and current Chelsea players. In December 2007 in a 4-4 draw against Aston Villa, Andriy Shevchenko scored the first penalty kick at the Shed End since Osgood's ashes were buried there.
With Southampton F.C.