A 12-year-old has scored 439 runs in a school cricket tournament in Mumbai that was used as a launch pad for the career of current Indian superstar Sachin Tendulkar, local media reported on Thursday.

Sarfaraz Khan faced 421 balls and hit 12 sixes and 56 boundaries for his Springfield Rizvi school against a hapless Indian Education Society in a three-day Harris Shield match on Wednesday, the Times of India reported.

It was in this tournament in 1988 when Tendulkar, then a prodigal 15-year-old, made 329 during a 664-run partnership with childhood friend Vinod Kambli, who also went on to play international cricket.

Tendulkar made his Test debut a year later and became the most successful batsman in history with a world record 12,773 runs and 42 hundreds in Tests and 16,993 runs and 44 centuries in one-dayers.

As television cameras and reporters surrounded the young Khan after his mammoth knock, he joked that it was easier scoring 400 than posing for the media.

"I swear I will never hit another 400 in my life," the newspaper quoted Khan as saying. "Slogging on the field is way easier than posing."

The only time Khan took his eye off the ball was when his coach Raju Pathak signalled from the pavilion on the next target he needed to achieve, the paper said.

"I am a complete target person," said a confident Khan. "You tell me you want this and I'll give it to you.

"Once I touched my triple century, word came in about Sachin Tendulkar's mark of 358. That conquered, I managed 400. I was thrilled to bits."

Khan said the only time he had seen Tendulkar from up close was during the Indian Premier League last year when the master was giving batting tips to Mohammad Ashraful, a former captain of Bangladesh.

"I heard him tell Ashraful to watch the ball till the last moment before it left the bowler's hand, so that he gets more time to adjust his shot," said Khan.

"I have followed that advice and it has got me a lot of runs."