Aston Villa twice had to come from behind to earn a 2-2 draw at Wycombe Wanderers.
Matt Lowton, who signed a new four-year contract with Villa on Friday, headed his side back on level terms from Leandro Bacuna's cross midway through the first half after Martin McCoy had caught Brad Guzan unawares with a dipping cross-shot.
Wycombe went ahead for a second time just after the half-hour mark through Leon Johnson's header, but Ashley Westwood had the last word with a curling free-kick seven minutes into the second half.
Premier League new boys Crystal Palace edged Dagenham & Redbridge 2-1 at Victoria Road in their pre-season opener. Trialist Atdhe Nuhiu put the Eagles ahead 11 minutes before half-time, sweeping home Quincy Owusu-Abeyie's low cross, and Owen Garvan doubled their advantage from the penalty spot in the 56th minute after right-back Quade Taylor had been brought down by Afolabi Obafemi.
Medy Elito halved the deficit 12 minutes later, converting the second spot-kick of the game after Taylor had tripped Zavon Hines, but the Daggers could not find an equaliser.
West Ham suffered their first defeat of the pre-season programme, going down 4-1 against Mainz at the Stadion am Bruchweg.
The Hammers trailed 2-0 at half-time through goals from Dani Schahin and Nicolai Muller and, although Joe Cole volleyed the visitors back into contention at the start of the second period, Shawn Parker re-established the Bundesliga side's two-goal cushion by converting a controversial 74th-minute penalty and Sebastian Polter sealed matters four minutes later.
Hull City, who have been preparing for their return to the top flight at a warm-weather training camp in Portugal, played out a goalless draw with Sheffield Wednesday in Albufeira.
In a game of few clear-cut chances, the Tigers needed a goal-line clearance by Alex Bruce from Jermaine Johnson's effort to ensure they did not slip to defeat against their Yorkshire rivals.
Celtic showed continued signs of improvement as they registered their first pre-season victory with a 2-1 win over League One side Brentford. Amido Balde and Callum McGregor were on target for the Hoops after Adam Forshaw had given the hosts an early advantage.
Norwich lost 1-0 to San Jose Earthquakes in their pre-season friendly at the Buck Shaw Stadium.
New signings Ricky van Wolfswinkel and Leroy Fer played 45 minutes each, but could not prevent Cordell Cato's seventh-minute goal deciding the match.
Canaries boss Chris Hughton refused to be down beat, saying on the club website: "I thought Ricky looked really sharp and Leroy was prepared to get on the ball and show some of the qualities of his game, but there were a lot of pluses."