The Chess Player (Kling & Horwitz), vol.i no.17, Nov. 8th 1851, p.134:

A match has commenced between Messrs. Staunton and Williams, Mr. Staunton giving his opponent three games at starting. The player who first scores seven games to be the winner.

The end of the match is reported in the same magazine for the week dated November 29th (no.20, p.158). The following number reports (p.176):

We hear Mr. Staunton has offered to play another match with Mr. Williams, giving three games out of seven, for a larger stake, providing each player be limited to half an hour in making his move.

From a letter by Oxoniensis (Robert Barnett Brien) in the Chess Player's Chronicle, 1852, p.217:

But still, I shall be told, we have a private match to deal with. I wish, for Mr. Staunton's sake, and for the sake of chess, that the match in question had not been a private one; as we should then have had some chance of escaping proceedings of a flagitious character. It is now time that the public should be fully acquainted with the circumstances of the case. I can well appreciate Mr. Staunton's delicacy in not exposing them to the world; but he will forgive me, I trust, making the remark that his enemies have courted this exposure, and exposure they ought to have. Mr. Williams' aide-de-camp states that three games were given Mr. Williams, on condition that the match should be played at Cheshunt. The following were the real facts of the case: On the Committee of the Tournament choosing Mr. Staunton to play a match with Mr. Williams, the latter refused to play on even terms, and alleged his desire of rest and country air. Hereupon, his opponent, in the most handsome manner, offered him that rest at his own country residence, and agreed to give him three games out of seven. The sequel is known, but not to its full extent. The guest (we have the impartial testimony of the distinguished foreigner, Lowenthal, who was present during a great part of the contest) finding, as he confesses, that even with such odds given him, he had not a shadow of a chance in play, did his best to wear out his invalid host. Upon some occasions he did not appear until mid-day had passed, in order that the game might be protracted to midnight. At others he did not appear at all, but sent the most frivolous excuses. The morality of this proceeding I leave to him and his wretched supporters. If they feel aggrieved by these remarks, let them remember Mr. Staunton's offer to give Mr. Williams the same odds in a match for 100 guineas, provided that a limit be fixed to the time occupied upon single moves, and let the brave spirits act accordingly.