delivered the opinion of the Court.

In this action an attorney is seeking to recover compensation for his professional services, and both parties have *43appealed from the judgment, the defendant because he was adjudged to pay a certain sum of money and the plaintiff because the judgment was not for the whole amount claimed. The proof was heard after a default had been entered against the defendant, who maintains on appeal that the judgment should be reversed because the complaint does not state a cause of action in that it fails to set forth the essential allegation that the services for which compensation is claimed had been rendered at the request of the defendant. The complaint contains no such allegation, but the plaintiff urges that the evidence supplied this omission and that the complaint should be considered as having been amended.

Said allegation is really essential in this-hind of complaints, as it establishes the contractual relation between the parties, and hence could not be supplied by the evidence; nor should the complaint be considered as having been amended, nor could it be amended, since, as stated by us in Suárez v. Succession of Lanausse, 42 P.R.R. 335, where, after the defendant has defaulted, the complaint is amended in matter of substance, the amendment opens the case in default, and a valid judgment can not thereafter be entered based on such amended complaint, unless the defaulting’ defendant is served with the amended pleading and given an opportunity to plead.

The judgment appealed from must be reversed and the case remanded to the lower court for further proceedings.