Virender Sehwag is one of those frustrating batsmen whose performances vary wildly between sheer brilliance and abject failure. He has been out of favor with the Indian selectors for some time, particularly for test cricket, but he’s been given a chance again for India’s home test series against South Africa, and my how he has taken it.

The first test is taking place in Chennai. South Africa won the toss and elected to bat, and that looked like a wise choice because they did very well, registering 540 all out. Several of their top batsmen got big scores, including 159 from Hashim Amla. India are now batting, and they have got to 468, for the loss of just one wicket. Of those 468 runs, Sehwag has 309, and he has made those runs off just 292 balls.

How good is that? Well, it is almost certainly the fastest ever 300 in test cricket (we can’t be totally sure because in the early days of the sport the number of balls faced wasn’t always recorded). Sehwag has become only the third player (after Sir Donald Bradman and Brian Lara) to score over 300 twice in a test career. He previous best was also 309, against Pakistan, but then he was out. In this game he still has a chance of improving on his score. He is currently 18th in the all-time list of highest single-innings scores. Given how well the pitch is playing, he must stand a very good chance of overtaking Lara’s world record of 400.

Unless pitch conditions deteriorate markedly, the game is probably doomed to a draw, but the eyes of the cricket world will all be on Chennai for the next day to see is Sehwag can get that record. If you don’t have TV coverage you can get ball-by-ball text commentary on CricInfo here.