Crystal Palace midfielder Eberechi Eze thought he had given his side the lead with a well struck free-kick within the opening 15 minutes at Stamford Bridge.
Sunderland sign France defender Nordi Mukiele from Paris St-Germain for an initial £9.5m plus £2.5m in add-ons to take their summer spending to about £141.5m.
West Ham vice-chair Karren Brady says the club "won't panic" and manager Graham Potter will be given time to turn things around following a disappointing defeat by Sunderland in their Premier League opener.