John Terry officially joined Twitter on Saturday morning.

The Chelsea legend has been active in the past 24 hours, having already tweeted 46 times.

And it hasn't taken him long at all to clash with Manchester United fans.

When ex-England cricketer Kevin Pietersen sent a post welcoming Terry to Twitter, a United fan decided to mock him for his slip during the Champions League final penalty shootout in 2008.

"The same John Terry, Kev?" @yeatesy46 wrote, alongside a video of Terry missing the penalty.

Terry wasn't amused as he referenced the amount of trophies he won at Chelsea and mocked the fan's literacy.

Terry couldn't resist firing another dig as he referenced United's loss to Man City in another reply.

@yeatesy46 ended up deleting their original tweet.

Terry also clashed with another United fan who mentioned the 2008 Champions League final.

"Welcome to the wonderful world of Twitter! #ThatNightInMoscow," @MUFCFanZone2 sent to Terry, accompanied with an image of the Chelsea man crying after his side's loss.

Terry replied: "That’s the Man Utd fans after today and realising your 5 years away from catching Chelsea."

Ouch. Terry also gave his thoughts on United's defeat to City at Old Trafford.

He praised Pep Guardiola and City, stating they are far superior to Ole Gunnar Solskjaer's side.

He wrote: "Two teams who are worlds apart. Man City are a joy to watch in possession, and a great example to teams nowhere near as good as them out of possession.

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"Pep drives and demands that from every single player, every ship needs one captain and he is the best."

If Terry's first day on Twitter was anything to go by, it seems his account will feature comedy on a regular basis.