LONDON (AP) — A late header by Laurent Koscielny capped a spirited comeback for Arsenal as they drew 2-2 against Napoli before a home crowd at the Emirates Cup on Saturday. Earlier, Galatasaray beat FC Porto 1-0 to take a lead in the two-day preseason tournament.

Arsenal was down 2-0 at halftime after clinical strikes by Napoli's forwards caught them off guard, with Lorenzo Insigne taking advantage of a defensive blunder by Carl Jenkinson in the seventh minute to open the scoring. A long pass from Marek Hamsik 20 minutes later found winger Goran Pandev, who cut wide and curled the ball in from a tight angle.

Arsenal had a chance to equalize on a penalty between those goals, when Napoli's Valon Behrami felled Kieran Gibbs in the box. But Lukas Podolski was denied by Napoli's newly-signed goalkeeper, Pepe Reina.

Arsenal manager Arsene Wenger reacted in the second half by inserting Theo Walcott for pace on the right flank and the team pressed higher up the pitch, dominating possession and creating multiple chances.

Olivier Giroud pulled one back with a spectacular overhead kick goal from a corner and almost added a second two minutes later with a header. But it was Koscielny who leveled the score with three minutes to go before the end of regular time. The French center-back headed home the ball after Reina had made a stunning save on a header by Per Mertesacker.

Wenger declared himself satisfied with his players' response. He said they suffered early on because they were not pressing enough, something the Italian team took advantage of.

"They are good at counterattacking. It took us some time to adjust defensively," Wenger said.

He refused to be drawn about Arsenal's attempts to sign Liverpool forward Luis Suarez, saying negotiations were ongoing.

In the first match of the Emirates Cup, Turkey's Galatasaray beat Portugal's Porto in a match decided by penalties.

Galatasaray's Felipe Melo converted one in the 71st minute after a run into the box by defender Emmanuel Eboue, who was playing at the Emirates Stadium for the first time since leaving Arsenal in 2011.

Porto had dominated possession in the early stages but could not capitalize on its opportunities. Jackson Martinez was denied on the first penalty by Galatasaray's goalkeeper Fernando Muslera early in the first half while Lucho Gonzalez failed to equalize late in the match, drawing his spot kick wide to the left.

Galatasaray grew in confidence in the second half, with Didier Drogba and Wesley Sneijder linking up effectively and testing Muslera on several occasions. Porto had to rely on counterattacks, in particular on the speed of their Brazilian winger Kelvin.

Galatasaray coach Fatih Terim acknowledged his side was lucky to earn full points from the match.

"In the first half Porto was better than us. Our play wasn't very satisfactory but in the second half we pressed more and we performed better," Terim said.

He decried mistakes in defense that had conceded the two penalties and exposed the goal, but said the team was still feeling the after-effects of preseason training.

After the first two matches, Galatasaray leads the tournament with four points — three for winning and one for a goal. Arsenal and Napoli follow with three points each and Porto lag with none.

The Emirates Cup concludes on Sunday, with Napoli playing Porto before Arsenal takes on Galatasaray.